I am building a new shower with both 3/4 and 1/2" supplies on opposite sides of the space. I intend to have multiple body sprays and a shower head on the 3/4 side, and one spray and head on the 1/2 side. I am in need of info about what types of valve(s) I can use to simplify and reduce cost. Are valves available that would have multiple stops for various combinations of the outlets as I have described above? Will I instead have to use a pair of temp and diverter valves, on each side? What do you think?

If you just wish t install a single shower valve check out these two sites I have found for shower transfer valves;
http://catalog.asme.org/Codes/PrintBook/A112187_1999_Deck_Mounted.cfm

http://www.insidestore.com/jump.jsp?itemType=PRODUCT&itemID=8972
Good luck, Tom