Having finally found the inspiration to do so, I present you
The Sublime Ur-Lyrist v2.0
Or: Mystic Theurge, eat your heart out. By the way, you suck.
Special credit to Hazren for pointing out the possibility of using Chameleon to meet Sublime Chord's Prerequisites.
Race - Human. Those extra skill points will be needed.
Attributes (32 pb): Str 8, Dex 8, Con 8, Int 18, Wis 14, Cha 16. Wis and Cha are our casting attributes, the high Int modifier is needed for the large number of skill points we have to purchase. When all relevant skill ranks are purchased and set in stone, we can rebuild some Int points into our casting attributes, since skill points are not retroactive (i.e. when you lose or gain Intelligence, you do not lose or gain skill points you earned at earlier levels).
Level breakdown
Level 1
Factotum 1 - Able Learner, Iron Will. The combination of a single level of Factotum and the Able Learner feat gives us all skills as class skills for the rest of our carreer. Iron Will is needed to qualify for Ur-Priest. Between our +4 Int Mod, 6+Int skill points, and being human, we get 11 skill points per level, or 44 at level 1. Max out Knowledge (Nature), Knowledge (Arcana), Knowledge (Religion), Knowledge (The planes), Perform (String Instruments), Diplomacy, Gather Information, Sleight of Hand, Listen, Bluff, and Spellcraft.
Level 2
Bard 1 - Keep the skills from last level maxxed out.
Level 3
Bard 2 - Spell Focus (Evil). Since we need only 5 ranks in Knowledge (The planes), we can drop that now and put the extra point in Decipher Script instead.
Level 4
Bard 3 - We'll put our stat increase in Cha here. Since we now have 6 ranks in Spellcraft and Bluff, we can stop worrying about them for now and put the two points in Profession (Astrologer) instead. Otherwise, as before. Our skill ranks should now look like this: Bluff 6, Decipher Script 2, Diplomacy 7, Gather Information 7, Knowledge (Arcana, nature, religion) 7, Knowledge (The Planes) 5, Listen 7, Perform (String Instruments) 7, Profession (Astrologer) 2, Sleight of Hand 7, Spellcraft 6. After this level, the pressure on our skill points eases up considerably, as many of the skill requirements for Fochlucan Lyrist cap at 7.
Level 5
Bard 4 - At this level we can stop maxxing Knowledge (Nature), Diplomacy, Gather Information, and Sleight of Hand. This frees up skill points for Decipher Script and Profession. That means 3 ranks for each from the freed-up skills (including Bluff and Spellcraft), plus one rank each for the level, and we've got all we need. Our ranks are now Bluff 6, Decipher Script 6, Diplomacy 7, Gather Information 7, Knowledge (Arcana, religion) 8, Knowledge (Nature) 7, Knowledge (The Planes) 5, Listen 8, Perform (String Instruments) 8, Profession (Astrologer) 6, Sleight of Hand 7, Spellcraft 6.
Level 6
Bard 5 - Leadership. Get a cohort (Anything, really. I'd recommend the same build as you. Or perhaps a bodyguard.) and a bunch of followers. Make one of the followers be a druid and have him teach you Druidic. This will turn him into an useless ex-Druid, so have him trigger the next best trap and get a new one. Since our leadership score (9) won't allow for followers yet, we'll buy a Cloak of Charisma +2 in order to get it to 10. As for skills, we continue maxxing Knowledge (Arcana), Listen, and Perform. We'll put two more ranks into Spellcraft in order to meet the Ur-Priest prerequisites, as well as a rank into speak language for Druidic. Four skill points go into Sense Motive, and the last two into pretty much anything. This level will be rebuilt later into Chameleon, losing us two skill points. Guess which ones will have to go.
Level 7
Bard 6 - We keep maxxing Knowledge (Arcana), Listen, and Perform. The remaining 8 points go into Disguise. Two of these will be lost when we rebuild this level into Chameleon. Somewhen within this level, if in an ongoing campaign that started before level 8, we rebuild our Int down to 14 (and buy a Headband of Intelligence +2 to enable 3rd-level chameleon casting, note that the spells per day is 0, so we need an Int bonus of +3 to be able to cast 3rd-level spells) and our Wis up to 17.
Level 8
Bard 7 - Another Stat increase to Cha. This is the last level of Bard we need to qualify for Sublime Chord's casting prerequisite. We continue maxxing Arcana, isten, and Perform, four points into Disguise, and the rest doesn't matter.
Level 9
Cleric 1 - Open feat slot. This level is just to qualify for Ur-Priest's Fort save requirement, really. Clerics only get 2+Int skill points, but thanks to the extra skill point from being human and out +2 Int modifier we can still keep all three relevant skills maxxed. If you have been paying attention until now, you know what those are.
Level 10
Ur-Priest 1 - Now the brokenness begins. At this level, we have reached all prerequistites for all classes we are going to take. We max the big three, and starting next level, we a) have absolute leeway with skill points, and more importantly, b) we stop sucking ass and instead start kicking said ass. This is also when we buy a Ring of Evasion in order to meet the pesky evasion prereq.
Level 11
Sublime Chord 1 - The moment (or rather, level) of truth. We now rebuild three bard levels (Since the entry specifically says "rounded up", we can rebuild three class leves instead of two even though 11/5 is only 2.2) into Chameleon. Since we still have 4 Bard levels left, we meet the bardic music prereq of Sublime chord and the bardic knowledge prereq of Fochlucan lyrist, so we're good. Chameleon oses us 2 skill points per level, but we wisely put extra ranks in Disguise, so we're good from that perspective too. This should go without saying, but we apply the CL increase of FL to Sublime Chord Spells, not bard spells. We can now cast 5th level arcane and 1st level divine spells.
Level 12
Fochlucan Lyrist 1 - Open Feat slot. We put the ability bonus into Wis. Now we rebuild three more Bard levels into Fochlucan Lyrist, leaving us with one as a safety cushion for reasons explained in my previous post. We now cast 7th level arcane and 5th level divine spells.
Level 13
Fochlucan Lyrist 5 - If the DM says we don't need Bard levels for Sublime Chord's Music and Knowledge progression to advance (and hasn't murdered us brutally yet), we can rebuild the Bard level into another FL level, giving us 8th level Arcane and 7th level divine spells. Investing in Tomes is a good idea, since we want to be able to cast all our spells without fear of having that ability stolen.
Level 14
Fochlucan Lyrist 6 or 7 - Depending on how the DM rules SC's Music and Knowledge progression to work, we now have either 8th level arcane and 7th level divine casting (if we need a level of Bard) or 8th level arcane and divine casting (if we don't). In the former case, the next two levels are in FL, and after that it's whatever the heck we want. In the latter case, the next level is FL, and after that it's whatever the heck we want. If we're worried about losing our Ring of Evasion and pretty much all our Win along with it, we can take two levels in Rogue, Monk, or Survivor (those three are the easiest to get in). I'd go with Survivor since it also gives us three good saves and Uncanny Dodge in two levels, as opposed to Rogues Trapfinding and Sneak Attack +1d6, and the Monk... *shudder* Monk and Rogue would only net us 1 BAB over Survivor, and we have more spells per day than we have hit points, so why would we be making atacks other than touch attacks? We can't rebuild the Cleric level until we have the 8th level of FL, since otherwise we wouldn't meet the Fort base save prerequisite for Ur-Priest anymore, so I'd say we just rebuild it into Survivor.
Summary
We get 9th level spells from two awesome lists and one okay list, as well as 3rd level spells from any list we want - at level 16 (15 for non-bards), when we're supposed to have access to 8th level spells from a single list. The final build is as follows:
Factotum 1/Bard 1/Cleric 1/Ur-Priest 1/Sublime Chord 1/Chameleon 3/Fochlucan Lyrist 8 or
Factotum 1/Cleric 1/Ur-Priest 1/Sublime Chord 1/Chameleon 3/Fochlucan Lyrist 8
Feats: Able Learner, Iron Will, Spell Focus (Evil), Leadership, Open slot, Open slot, Open slot
The build can, of course, be done without Factotum. I simply went with it in order to go easy on what little is left of my sanity.