Bandit vs Level 79 Wizard in Skyrim 

You get it at the end of the college of winterhold quest

Arch mages robes from College of Winterhold, Mage's Circlet Crown, Minor Magica ring. I have more than 600 Magica along with 500 HP. Also, Silent casting spells perk to maintain stealth. Most of my illusion and conjuration spells cost less magica and I have a good amout of magica regeneration thanks to my gear. You can also use Atherium Crown instead of mage's Circlet and put 2 mage stone blessings to progress your mage skill trees much faster.

nice, have you considered using the ring of the erudite? depends on which side you pick on the dawnguard dlc questline