A dip into fighter is typical of many gish builds. I think wizard 6 / fighter 1 / spellsword 1 / abjurant champion 5 is the typical beginning. That leaves you at 13th level with 12th-level casting, base attack bonus +10, and -10% arcane spell failure chance from armor.

Is Dragon magazine on the table? The Armored Savant ACF (Dragon 355, p92) trades the 1st level bonus feat for an ability that cuts arcane spell failure from armor in half. (It also lets you treat any armor as one category lighter for determining movement.) So you can cut full plate down from 35% to... 17.5%? Maybe there should be some form of rounding. And you can cut mechanus gear down from 50% to 25%.

Mithril is -10%, and since mithril makes the armor medium, Armored Savant then lets you treat it as light for movement. A thistledown suit (Races of the Wild, p168) gives -5%.