Steve, There is a kit (or you can just buy the pcb) produced by Sam, G4DDK.? I have no connection with him other than having bought one of his boards.
Another possibility is look at the io group
[email protected]?
This group is run by Chris Bryant, G3WIE.? This is more up to you how you go about it, and might mean getting your own board made from a loow cost pcb supplier. I think all the necessary information is there if you want to built it.?
Tony
G4CIZ