Blade, Mysticism, Restoration, Alteration, Heavy Armor, Armorer, Mercantile?
Certainly not an optimum build, but I imagine it'd be fun to play around with- the character would focus on buying, collecting, and maintaining all sorts of enchanted blades to make up for his "lack of formal training" in the arts of Destruction? Seems like something those snooty High Elves would do
Maybe go for the Mage sign for extra magicka without the Apprentice weakness?
Or go Atronach and replace Mercantile with alchemy... Really, all three magic-based birth signs would dramatically alter how this character would be played I'd think.