I just got done doing my research and went with the clifford.. I liked the intergrated water jacket and the open peluim for the forward mounting of the carb, also the pros at Clifford we more than happy to talk to me on the phone when I needed a little advice on which way I wanted to plumb the water jacket. I do not believe offy has any support.. And this is just my option but I prefer the look of the Clifford.
Check out Inliners.org then click on the tech link and then the link for throttle linkage for some great info on mounting a carb to a offey if you go that way.
http://www.inliners.org/