The C41W and the WVB are due to be released nation wide tomorrow March 13 both weaknees.com and solidsignal.com are shipping them now. You will need one WVB for any number (solid signal says only 3 per WVB) of C41W, you can have up to 8 minis in any combination but only 3 at a time will connect to the Genie. The WVB is connected to the SWM system with coax and the range is about 80 ft YMMV and you can have more then 1 WVB to cover the whole house if needed.
I prefer the wired option also.