Can you please give ne your recommendations
For that build, I'd favor a follower that uses mostly ranged attacks, either a ranger/rogue type or a mage. Be careful selecting a mage follower though, as some of them favor area of effect spells and you can take damage from that.
http://www.uesp.net/wiki/Skyrim:Followers
I've used Marcurio before - he's a good choice.
Janessa is a pretty good all around companion.She's skilled in archery, one-handed and block, she's pretty stealthy so she can keep up and not get you busted. IMO you want an all around good companion, Janessa is the way to go
I try and not use the mage companions, for the very reason that's been mentioned. They can and will hit you with magic, not saying that you won't catch an arrow from time to time but the magic hurts more
It usually impedes your vision as well when in first person and engulfed in flame, an arrow does not That being said though......Tis just my opinion, I myself don't really like magic using companions. I prefer someone who wields a box,sword,axe etc...etc...
Magic casters do have their good points, such as dealing more damage with certain spells against certain enemies, like fire on the undead and what not. But it's still not my cup o'tea.