I just saw a custom Clark Board TK 22 case currently on Ebay. Seller is madlmax88. I bought a couple from him a month ago. Shipped from Moscow, and took about 3 weeks. They are pretty nifty. He also sells cases for the IBU stuff. Try a search for "TK-20 & TK-22 board housing protector box case"

Not from the U.S. I know, but no other retailer exists that I know of. Seems to be the only game in town...