I wound up talking to a Givi engineer and he advised me to go with the S150 universal top rack, so here's how it came out. Wasn't too difficult to install, though the ridges on the box were a little bit of a bitch. Now I can lash my tent and a camping stool to the bike and have room for all of my other shit. It looks ok, I'm not completely sold on it. About to hit the road for a 5k trip to Austin for MotoGP and then off to Key West, so I'll report back if the damn lid rips off.