Double posting for awesomesauce value :
Thaumaturge 4/Metaphysical Spellshaper 3/Seeker of the Lost Wizard Traditions 3/Incantatrix 10-2 to final metamagic, -1 to each metamagic, uncapped spells, free metamagic from both MPSS and Inca, Spell Reflection to ricochet spells back off an enemy a bunch of times, scroll prep to use any scroll as an impromptu spellbook, AoE spells always use all their potential area if you so desire, and if you don't feel this last ability is needed, replace the 3rd level of Seeker with Tainted Sorcerer, for even more free metamagic. Between that, MPSS's easily abused ability damage mechanic, and Inca getting it for free (basically), there shouldn't be a single combo out of reach.
Also, if you'd rather dedicate a bit more to seeker, go for at least 5th level, and go monster hunting with Harvest Magic, for basically free crafting by scavenging the corpse of magically inclined monsters you overpower with your obscene magical might.
Feats and Items of note :
-Miser with Magic, for a no-action recharge, usable 1/rd with Persistent Unfettered Heroism
-Initiate of Mystra, as you share the cleric list with clerics
-True Believer isn't needed, as you only need to sacrifice a 5th level divine spell slot to use...
-A Tome of Ancient Lore, for all the spells known outside of core you'll ever need
Let me know if I missed anything
If you get the Tome before entering Incantatrix, you can even snag all the spells of the school you're going to ban, and not be out a damn thing.