A hunter duo has insane DPS and you'll be "soloing" elites by the time they're orange-con and farming Wailing Caverns for deviate scales at level 18. Positioning is a bit of a bastard, solved by sticking your first three talent points in Hawk Eye and by making a macro that does nothing on your main - but moves your alt a few steps forward to stand in line with the main.

Then you nuke. 100+ DPS with crafted leather at level 18 in fights, not a perfect measurement because anything I attack goes down pretty fast.

With a priest the pet will live a lot longer and maybe even hit harder if the priest gets the right spec, but I don't think a priest will help the largest problem a hunter has - the pet has to keep aggro. I say, duo up some ranged nukers to level six or so, since you're just starting out.