Messed around on a good private server which doesn't have any isboxer support. Was a clunky setup and using 2 hunters killing stuff. Easily out kill mages grinding not sure how much fun that would be. Went one BM one Marks need the distance marks gives at 20. Single target health bars melt away and these where mobs 2 to 5 levels higher. Kiting was funny with 2 pets attacking while mob was chasing me.

Make sure your main hunter has Spirit going to need the mana regen... Also get some mana plus food for no downtime.

Also did hunter with druid which is a good combo as well. A lot of synergy. I was just using druid as heal bot and buff bot. Still going through mobs pretty well. Never any downtime either. Druid was adding dot, healing and the occasional wrath.

I would do skinning and alchemy for professions while your grinding to 60 and both setups benefit from it.