Grey elf wizard is the optimal choice for magic users, I think. Other combos I can think of, that I like: orcish priest, dwarven druid/wizard/priest (tougher than elves), hurthling/human/gnomish druid, drakeling druid/wizard, gnomish wizard/elementalist, trollish wizard (weirdly fun). I'm no big fan of elementalists or necromancers, but I like druids. Animals don't attack them, they tend to get good spells, and they're not as frail as wizards. Other interesting choices include elvish/drakish bards, and weaponsmiths (who have the needed skill (Concentration) to become good casters). As far as I gather, smithing is all about grinding, though, so it's up to you ...
Any magic user needs to get Concentration to 100% as soon as possible. Literacy is also very important. Important stats are Learning (how good do you memorize), Mana (amount/regeneration of mana) and Willpower (strength of magic). Choose the "Potent aura" talent as soon as possible.
As always,
Minotauros