Thanks for everyones comments. Im actually planning on building these wheels as a winter project, so redishing isnt a concern as its a new build. Yes, I really want the HG freehub body for the availability of cassettes. I happen to have the exage 126mm UG hubs sitting around. I just was trying to build wheels using parts I have that are serviceable so the HG body was more important to me than the number of speeds. Perhaps I will give it a try and see what happens.
...Thanks bjt