Ahh yes, the SPL w6v1 knockoffs. I have read alot about them, but not any reviews. They certainly do look like a carbon copy, even down to the t/s parameters.
Have you got a chance to listen to them yet?
As for a knockoff of chris's boxes, just glass them, it'll be alot easier imo.
http://www.zmods.org/forums/showthread.php?t=192
Just glass the sides up a couple inches further, and make the ring for a 10 instead of an 8