Welcome to the forums!

I'm playing around with a 5 hunter group as well - up to level 28 now, cleared RFK at 27 with no problems. Only had one toon die when I screwed up a pull (note to self - check for patrolling mobs before pulling :P).

Go BM spec, as it makes your pets much better tanks. I've decked them out with Great Stamina and Natural Armor skills as well, and will be giving them Cobra Reflexes & Avoidance as soon as I hit 30.

Choice of pets will be important. For instances, you can't go wrong with 5 owls - screech is great for holding agro on groups of mobs and you can mend pet and still not pull adds. Outside of instances, Wind Serpents offer great DPS - in fact I'm finding that, if I don't start shooting as soon as I send them in, they kill the mob and i get no exp!

I've gone 5 x engy for the Jumper Cables, guns and other goodies.

Cheers,
Shane