DD74 - That's the cool thing about Cafe racers. You can start with pretty much anything. Check out that KZ Souk posted. Beautiful and who'd a thunk it? Naturally, there are some bikes that lend to the conversion more readily. Check out the Benjies site -
http://www.benjiescaferacer.com/home.html
that will give you an idea as to what bikes have parts (somewhat) available. The Honda CBs are a natural as they are plentiful, cheap, and reliable. I have 2bikes I'm considering a conversion on - the 66 CB160 pictured above which is a very common cafe base, and a 75 CL360. Not as common but parts are available and I think the upswept pipes will look very cool straight and wrapped.
Jim - Do you mean the Borile?
http://www.caferace.com/borile.html