If you can put together a full 5 man group that doesn't involve random players from LFG, then I don't see why you couldn't just setup Dungeon Buddy to do exactly what you want it to for at least the Heroics. Just set up the tank bot as the leader and then add the other 4 as "followers" in the config. I don't know if LFR is supported but I bet Lazy Raider might work for that.