I don't know if Chameleon is legal, but if always choosing Arcane Focus as your Aptitude Focus counts as having 3rd lvl arcane spells (for SC) then this seems like a very powerful build:
For a human (with high wisdom and charisma. Moderate intelligence needed, maybe.)
Rogue 2 [evasion and skills]
Druid 1 [druidic. +2 fort save. Perhaps even use the variant that gives Wis mod to AC, when unarmored. Ur priest might not violate the druid code, so all you'd lose is spellcasting.]
Bard 2 [bardic knowledge and skills. The music is nice too.]
Chameleon 3 [3rd lvl arcane spells, and the last +1 to the fort save]
Ur Priest 2 [more than 1st lvl divine spells and super fast divine progression]
Sublime Chord 2 [quicker arcane progression]
Fochlucan Lyrist 8 [onwards to double 9s]
1: Iron Will
1h: Able Learner
3: Malign Spell Focus (or Spell Focus (evil) depending on which version of Ur priest)
6: Extend Spell
8c: Free floating feat... Super useful.
9: Persistent Spell
12: Divine Metamagic (Persist)
15: Extra Turning
18: Extra Turning or (Alternative Source Spell, which theoretically might allow you to persist an arcane spell you know instead)
(For example, persisting something fun like Sirine's Grace could boost your AC and perform up quite a bit.)
(The feats from 6 onwards are up to you though.)
This gets double 9's, and a decent number of lvl 9 spell slots.
Persist Divine Power for BAB, if you really care about that. You have 14 otherwise, which is probably fine. With all your spell slots, you'd probably be casting spells the whole time.
You can also have fun with Inspire Courage too.
And your free-floating feat could be used to craft items.