I've noticed its basically impossible to get a group through the finder for a dungeon, either people just leave straight away or people don't really know what they are doing with healer/tank.
we aren't a guild based on dungeon in but I'm sure you'll find someone to do it with, we are trying to become a dungeon guild mainly but more people need to join, we are in DC aswell, message me if you are interest at: HyprrInfected