Raw Acoustics sells a kit like this I believe, and there are several designs floating around as well. Might want to try the Madisound forums, this is where all the DIY gurus hang out. I built the MBOW-1's from murphyblaster.com and they are very impressive for the $$ if you are interested in a monitor, you can always make it a floorstander and just seal the bottom of the cabinet.
