Pure melee - There has been a bit of chatter lately about GM's randomly summoning melee types that they believe to be boxing and running stuff like mq2melee. Enough anyway that while I still run it on all but my tanks I never use stickrange anymore because of it. If that is something you may be concerned about as well then that would rule out pure melee classes for you too. If not then the rog would prolly be your best bet with their BS's so long as your fighting in nice open spot where they wont get hung up on landscape like tree's.
Hybrids - not many fit well in a kite group situation even if there is rare chance of straight up fights (non kiting).
Ranger with their endless quiver and various bow AA make them ok dps but really are not going to give you a real advantage. Hands free sure but nothing special and a decent macro for another class would be better.
Bst with their pets also not bad but wouldnt really make as much of a difference in fights as some others... Really the bst class is one that I think could use some attention from SoE. They peaked around DoD/PoR and havent seen much in the way of improvements since then.
Priest - Clr ruled out immediately due to mercs.
Dru have some nice heals at higher end, ports, backup snare, and ok dots/nukes but other than ports in kiting situations wouldnt be a real great fit.
Shm is your best bet priest class wise due to their dots being decent, buffs increasing survivability and dmg output (minimally) on pets, debuffs like Malo or straight up incapacitate, slows. Tho the slows will only come into play if you pick up tank merc on one box and merc clr on 2nd box for straight up fights.
Int Casters - I saw you ruled out wiz/mage but imo they are honestly the best fit for your box set so I'm going to including their pro's/con's anyway.
Enc I honestly dont know much about since I havent taken above mid 50's but crowd control on a bad split could help and tash line would help with some of your dot resist. Beyond that I dont really know much about their pet strength or nuke power.
Wiz like dru have the benefit of ports and while they lack the dru ability to patch heal they do have backup snares and their nukes are the best in game with AA's that increase their likely hood of crit'ing much more than any other class out there. There are macro's out there that make them very viable alternatives as a box even allowing you to determine when they begin nuking so you dont have to worry about them stealing agro. If you cant find one you like PM me and I'll give you mine.
Mages best fit hands down!! Pet kits, CoH for help with splits, pets strongest in game with the ability to BS, stun, root, nuke(depending on pet type) and they can even tank for short periods of time if you get in trouble. Mages nukes are also very decent with an AA line for malo to help resist. Dev's magebot macro makes the class totally hands free and a force to consider on their own. I just started a mage myself about 6mo ago and I am already able to run that mac afk with just a merc healer in Vald with pet tanking!! Kiting you can use the water pet for his BS'ing or the air pet for stuns to give you more room for renewing dots or just time to maneuver in tight kiting area's. An air pet wouldnt totally replace a slow class in straight up fights but the stun does hit frequently enough that it would certainly up the survivability of your merc tank.
