I like using sneak and shadow to get close to people and cutting them up with my sword before they know what hit them...sneak and shadow is also good for getting free stuff. But I also want to be a powerfull wizard. From what I've read the only way to become a very powerfull wizard is to start out in the mage class.

Any thoughts on a starting character that would best suite my desires

Ok, I know I want to be a fighter mage sneak.

Would it be better to have the cross of mage/fighter/sneak which will only give you a magica of 120 or have a cross of mage/fighter with a magica of 180 and learn to sneak?
I guess the question is can I end up as powerful a mage with the start of 120 as I can starting with 180?

also if I don't choose illusion can I still make shadow spells?