I have a racing buddy who put a superbike tail on his 1000SS. He cut his entire rear subframe off, and fabricated a new one out of aluminum. I'm sure it was a fair bit of work, but he shaved off a lot of weight. He split for Barber this morning [CCS/Formula USA weekend]. If you want, I could take some pics when he gets back.
When I put my sharkskinz SS tail on my 750ss racebike, I left the subframe in place [cutting mine off will be this winters project] and bent all my support work out of 1/8" x 1" aluminum flat stock. It has held up very well, even through a fairly violent crash.