Only way you'll be able to farm heroics is to have a full group of five. As for class combination, Paladin/Warrior + Mage + 2 Warlocks + Priest should be fairly solid. Possibly swapping out the warlocks for Shammies if you feel the need. Kiting Heroics is probably the most haphazard way of doing it, as with some mobs you need a lot of space, and if you run into a patrol, you dead. Elementals weren't really the best tanks for bosses, Paladin/Bear Form/Warrior are the only real options.