So, a Sublime Chord-based Jade Phoenix Mage is not something new. However, what I haven't seen is a Duskblade base. I'm not sure if Arcane Channeling can be used with a Strike maneuver, but if it can, the synergy of delivering your favorite touch spell while smashing your opponent's face in with your favorite maneuver is bound to be tasty. So, here's the build. The Athasian Bard is in the Dark Sun Campaign Setting; I use it here because it's superior to Bard in every way for this build, since we don't care about the spellcasting it grants and the Athasian Bard is a nonspellcasting variant. Essentially you get all good saves, and a +1 bonus on Bluff and Sleight of Hand checks at first level in exchange for your spellcasting (there are later changes as well, obviously, but they're irrelevant here). You can use normal Bard if you prefer.
Duskblade 4/Crusader 1/Abjurant Champion 3/Athasian Bard 1/Jade Phoenix Mage 1/Sublime Chord 1/Abjurant Champion +2/Jade Phoenix Mage +7
Feats you need to take:
At 1st - Necromantic Bloodline - Retrained to Fiendish Bloodline
At 3rd - Versatile Spellcaster
At 9th - Practiced Spellcaster - To Be Retrained
At 12th - Arcane Disciple (Luck)
All your other feats are free, although since the idea here is to generate one massive, head-smashingly awesome attack, I heartily recommend Power Attack and your favorite accompaniments. I also recommend Power in the Blood from Dragon Compendium, as it will give you an extra spell of 4th level and up (explanation below).
So here's how this works. You need to be able to cast 3rd level spells to get into Sublime Chord, but you don't get them as a Duskblade for far too long. You get 2nd level spells easily enough, which is where Versatile Spellcaster comes in. Now, the problem is, ordinarily you don't know any 3rd level spells. Fortunately, Bloodline feats (see Dragon Compendium) grant you an extra spell known for each level 1 through 9, and don't require you to actually have those slots in order to know the spell. So you can use your 2nd level spell slots to cast a 3rd level spell, and BAM, you can get in. Unfortunately for us, Sublime Chord actually lowers our Duskblade caster level; since it is based on class levels, your CL in all classes becomes 5 as soon as you take your first Sublime Chord level and stays that far behind until you finish Abjurant Champion, which kindly resets our Sublime Chord CL (and therefore every other CL) at 19, our BAB. That's why you want to take Practiced Spellcaster before Sublime Chord, but you can retrain it once it no longer matters. Arcane Disciple (Luck) will let us learn Miracle as our single 9th level spell known, which is just tasty.
Now, as to our choices of Bloodline: Necromantic gives Touch spells, and actually decent ones. These are invaluable to your low-level Duskblade, who would otherwise have to spend precious Spells Known on them, and you already have to take Lesser Deflect to qualify for Abjurant Champion. Once you have Sublime Chord casting, you will probably want to trade this out for a Bloodline that grants useful high-level spellcasting, and apply it to Sublime Chord instead of Duskblade. We make the choice of Fiendish bloodline here, but it's really up to you.
So what does this get us?
9th level spells, 6th level maneuvers (yeah, not spectacular, but not exactly BAD either), +19 BAB and therefore CL, and JUST enough Bardic Music to spend some of your free feats and wealth optimizing Inspire Courage. Obviously you want Arcane Strike, because having even more nova potential is just great. And because you took the Fiendish Bloodline, you can channel imprisonment, which honestly isn't all that great, except that it means some archaeologist in the future is going to have the shock of his life when he uncovers your hapless foe frozen in the act of exploding from your attack. Plus, you have no 3rd level spell slots, which I find to be hilarious.
And you still have a race to pick and over half your feats to spend, so it's surprisingly versatile. You can take Warblade instead of Crusader if you want, I just thought the maneuvers were a bit more appropriate for somebody who's already buffing the party. If Arcane Channeling can't be used during a Strike, and I'll be honest it probably can't, you can still hold the charge for scalding touch or something in between battles and use your spellcasting prowess to control the battlefield and suchlike when smashing faces won't solve everything.
EDIT: Also, buy a Drake Helm so you can learn shield, thus granting you +9 to AC in basically every battle ever. Also shivering touch, so that you too can make use of The Dragonslayer.