you are better off going Sorc 5 / Incantatrix 10 / Sorc +5 because you will already have full base attack all day from Divine Power.
Suggestion- pick the Competition domain instead of War, it allows you to learn Righteous Might and Greater Visage of the Deity as well as Divine Power (all insane good buffs to use with Instant Metamagic (persistent))
When you have to give up stuff to get something you will already have, buffed, you don't need it. Namely taking ACF's to get things like martial weapon proficiencies and armor and higher base attack bonuses from more prestiging; just keep it simple as I suggested, you only need PhB and the Forgotten Realms Player Guide for your 2 classes if you do.
If you have the option to do so, I suggest being a Draconic Human (template is from Races of the Dragon), it is a +1 level adjustment, but you could start the game with the level adjustment "bought off" according to UA buyoff rules. You get +2 str/con/cha, +1 nat armor, 2 natural claw attacks, and some other racial bonuses, AND [dragonblood] subtype - which allows you to take Practical Metamagic for your metamagic feats later on. If you can use Dragon Magazines, they also give you the option to take Easy Metamagic (insert metamagic feat) which does the same thing as Practical Metamagic, but only requires 6 ranks in Spellcraft and a metamagic feat to apply it to.
And don't forget about the feat Arcane Thesis - pick a favorite spell, post 6th level, that you want to metamagic the crap out of, and cast it at higher caster level AND all the metamagics will end up being +0 on it - because of the following feat list (for example, I'll use scorching ray)
Feats- flaw-Extend Spell, flaw-Persistent Spell, human-Iron Will, 1st- Eschew Materials, 3rd- Twin Spell, 6th- Arcane Disciple (competition), 6thINC- Easy Metamagic (persistent), 9th- Arcane Thesis (scorching ray), 9thINC- Practical Metamagic (persistent), 12th- Easy Metamagic (twin), 12thINC- Practical Metamagic (twin), 15th-Searing Spell, 15thINC- Empower Spell, 18th- Split Ray
-- Twinned, Split Ray, Empowered, Searing scorching ray (2nd level slot)- 8 rays that deal 4d6+(4d6/2) fire damage ignoring any fire resistance and still dealing half damage to immune targets. If you super focus on this combo, it can get very very sick, especially if you focus on the 4th level spell orb of fire.
Arcane Disciple requires wisdom, yes, so start with a 13 and buy a +6 wisdom item.
Instant Metamagic (persistent spell)- bite of the werebear (7th level slot) and greater visage of the deity (9th level slot)
Cast Persistent Extended wraith strike (7th level slot), divine power (9th level slot) and Persistent greater blink (9th level slot)
hope these ideas help a bit