Personally I always feel slightly dirty when min/maxing house rules, because the rules were instituted by the GM with the intent of making the game more fair and balanced. It doesn't stop me, but I still feel dirty
Anyhow, in this case I would
definitely go for a god-style mage (Conj/Master Specialist 10/etc), and look for dual threat elemental spells as a priority.
Kelgore's Grave Mist (PHB II)is now a 1st level spell, Acid Arrow is 1st, Incendiary Slime is 1st (identical to grease, but with a Scorching Ray built in! from Complete Mage), the Heart of X series from Complete Mage. All of the Orb spells are now cantrips. Summon Monster, when used to call an elemental, is a spell of that element.
I'd go on, but frankly I think the house rule is going to be revoked by 3rd level.
Oh, and since you have a huge int, you might as well spend it on solid cross-class skills too