That is some nice woodworking. It looks like your DIY handiwork. I wish I had the tools and experience to build my own cabinets for the GR woofers and seperate boxes for the amps like you have done. I would just order the servo amps and woofers and make the boxes myself! It seems like the Rythmik and GR combo is really fast and tight, and integrates well with speakers for stereo listening.
Thanks. Here's a thread with some more details that may interest you.
http://www.audiocircle.com/index.php?topic=77367.msg731965#msg731965Over on the GR Research forum there are folks that offer flat packs for most of the speaker cabinets. Very likely one of them can help you out with the cabinets, leaving you to do the glue-up, add a finish of your desire, and screw in the drivers.
Good luck and let us know how you make out.