Which Swtor Companion should I use ?

I have a level 42 Bounty Hunter Powertech Tank, which companion should I be using thru PvE leveling?

 

I like Torian for when i'm in tank spec. He does good Melee DPS and, since he stays close, you can keep Guard on him. Gault can be good as well. You most likely won't need much healing as tank, but on the occasion you do, Mako is always the fallback .(source):swtor4credits