Hey Seth,
I know my suggestions will probably be a lot different that everyone else, but...
Another night for 3eb, they have an empty date between their Ram's Head and 9:30?
Honda Civic Tour will be in the area June 4th, but they aren't playing on June 3rd. Cobra Starship was awesome at the Cartel show, and getting them back to the club might be a lot of fun. (Similiar to how Ram's Head booked Akon despite the Gwen Stefani Tour). Could team them with their labelmates The Hush Sound who have a very decent draw and haven't played the DC area in a while despite touring with bigger bands.
Just some thoughts, thanks!