since you are using mq2eskay for your shadowknight you can swap to the beza buffs instead of azia buffs with /shd usebeza true and turn off usetorrent so you are using bite for mana tap.
in general, you're going to have an easier time with a full group compared to a not-full group.
not only do you get an xp bonus for a full group (6th doesn't detract from xp dished out either), but your fights will be quicker and you'll have more support and such.
shm would go well (shm aren't great solo healers until they're 100ish+, but their buffs and dots might help you out a bit)
a bst might be a good idea - pet, adps, buffs, paragon/fparagon (mana)
Mercs are just kinda meh at this time.
even a f2p (one time autogranted) f2p cleric is going to be leaps and bounds better than a merc cleric