Summit, Jegs, pretty much everywhere has them. They are not cheap, they are about the same prices for the rears as Bilsteins, fronts are pricey but they come as a fully assembled unit (mounts, shock, spring, etc) They are also big beefy monotubes. They ride really nice and handle really well when you get on it. These were going on my car if I had kept it.
Rears:
http://www.summitracing.com/parts/EDL-34031/
Fronts
http://www.summitracing.com/parts/EDL-33031/
rear springs
http://www.summitracing.com/parts/EDL-5246/