That can be done with a Dragonblood substitution level at level 1. They get Draconic Heritage for free, lose their familiar, get UMD as a class skill and +2 to Knowledge (arcana).
That's a terrible trade. But if they replace Improved Initiative and bloodline of fire, they could get Draconic Toughness and Draconic Vigor. That would give them +6 hit points and some self-healing, +3 against sleep and paralysis, but -4 Init and -2d6 damage on Kelgore's Firebolt. So they'd be far less killy but far tougher, and they'd potentially be able to UMD a few scrolls of healing and whatnot.
@TotallyNotEvil, opinion? Should we switch to that? They'd lose damage, but 6HP stays relevant through levels 1-6 (getting a cap at 6 is great, btw!).
Dragonblood subtype also unlocks practical metamagic at level 6, and that's awesome with things like Fell Weaken or Sculpt Spell. On the other hand we could just give them all Arcane Thesis (Fireball) or watch them throw Silent Stilled Sculpted 10d6 fireballs at level 6 of we want to give them Metamagic feats.
@DragonParadox sorry if I missed it, but how do we generate stats for our Legion Sorcerers?