I was very hesitant on being able to do any heroics with barely any gear and wearing greens on my 4 DK's. So I got a few items from the AH, did a few normal 80 instances for rep and tried out some heroics today.
4 DK's and a healer~! Vyndree from here helped heal me :P
Went extremely smooth!! Did both Pinnacle and Azjol Nerub absolutely no problems, and completely doable. Never thought it would be possible but I suppose anything is if you try.