Ah good old Illusion play-style build, my absolute favorite.
Well IMHO you can forget armor of any type if you specialize in Illusion, use it along with alchemy, sneak and conjuration with alteration and restoration as minor schools with some enchanting as and when you feel like it and your good to go.
You don't even need to know invisibility spell, average skill of sneak with some potions, cast fury/rage and an atronach tank, watch the carnage, if anything gets close calm/fear it. Last man/thing standing and its playtime, fear it for a chase scenario, or calm it and just chill and chat before lopping its head off, this can be done with any mediocre sword or just blast its brains out with a fireball, rinse and repeat. oh and dont forget alchemy will make you rich beyond belief so owning all the houses, spells, clothing etc etc will be a realistic goal to attain.
This would be my build if your interested.
Race would be either Dunmer or Breton, either is good for the build, your choice for bonus in either conjuration or sneak.
Main skills, Illusion, Conjuration, sneak, alchemy.
Secondary skills, Alteration, restoration and enchanting. Although if your hidden or the enemy cant get near to you alteration is redundant apart from passive magic resist perks, restoration is to turn undead etc, and then maybe the odd perk in one handed for a little damage, but with a potion of 120% extra damage one handed i wouldnt worry too much.
The main key IMO to this build is using illusion to crowd control to your advantage and alchemy to buff your offense and spell duration, as well as buff your sneak skill or even invisibility even from level one. And with no armor it makes it more important to be cunning and not get caught. If you do get caught i hope you have lots of stamina or potions because it will be time to .. .. .. .. RUUUUUUUNNNNNNNNNNNNNNN