Now:
I'd say go with a Gorilla as a main tank, as it has excellent AoE tanking abilities and good damage mitigation. And then cats on the others, with growl turned off for excellent dps.

After 3.1:
- Any tenacity pet can train thunderstomp (the gorilla AoE ability) as it is a talent in the tenacity tree. So any tenacity pet will do for AoE tanking (gorilla/bear/boar etc..)
- And either keep cats for good dps, or change them for wolves for the new AP buff(which works on the hunter and the pet).

My main is a hunter