I went with the 4 locks one resto druid team, wonder if I picked the wrong healer but I have a 80 holy priest anyway so I can always swap later. The plan was to do demo to fel gaurd and then affliction to siphon life asap and just BG/grind mobs. I solo lved a 71 lock to 77 in no time by doting everything I could find and staying mobile so I figured instant hots would be the way to go with a team like this.

As far as instances go everything pre outland is easy and with a bit of work could be boxed with five of anything probably, and as I recall someone is doing 5x priest and clearing outland instances at lv, Northrend stuff might get hairy tho.