You might want to look up the Elemental Savant Prestige class in Tome & Blood or Complete Arcane; similar theme, but focusing on one element.
Also, you can mostly do that by using a specialist wizard (Evocation), and look into the
Variant Classes from Unearthed Arcana (which was declared OGC, for the most part.... so is available online....) for it's specialist wizard variant classes.