If you care about stealthing while miltiboxing then you have to go some form of druid rogue combination like Nodoze said. In my opinion druid tanks and healers take a lot of good gear to be able to compare to the other classes in those roles, so it's a harder road, but you can skip a lot of headaches with stealth.

If you dont care about stealth while boxing your group then you can actually replace any warrior in any comp with a combat rogue. People dont like to manage the combo points because it's very unforgiving in Classic, but if you can do that with macros then you wont see any difference boxing a rogue instead of a warrior. Im guessing you understand how WF works on rogues, but if not be sure to look it up.