Day/Night mage IMO.... I took Day mage... this quite sucks if youre still in the lower levels and are attacked by wolven in the night (yeah better save beforer every trip on the world map then, heh), but that doesnt mnatter anymore in the higher or even lower medium levels. But the +20% bonus at day rocks. And who starts a fight in the night (besides the weak wolves)? Really...
Chose the one that gives the most willpower at the start. Only child is good. If you're going to be evil, you can chose "sold your soul" and get a bonus to magick aptitude, but your alignment will stay evil for the whole game. As for Day/Night mages, I would chose day. Wolves are easy to slaughter, the REAL challenge for a mage is using unocking cantrip and not getting caught. That's where you REALLY need MA bonus, and stealing is a night kind of job
IIRC a gnome only child starts with 16 willpower. its quite easy to make an uber mage out of him. you only have ch of 4 though so you only have virgil for a while unless you want to spend a lot of points in ch. later in the game you can get +5 charisma with a good ma
Do the night mage & shop during the day. You can crawl dungones at night with a 100% MA yet still shop at the quality smith & inventor's shops during the day. For a Battlemage, try 1/2 Orc female Barbarian, or 1/2 Ogre Troll Offspring. Female Elf Sold her Soul, starts with 35% MA before she buys a spell. Just buy Harm & spend the rest of your first 5 CPs on CN & WP to raise your blue gauge. The Only Child lets you buy spells as soon as you hit the minimum level to buy it, but that's 5, 10, & 15th level. You can use a start that increases other needed stats & raise the WP in time for each level easily.