Try these guys - Ducati luggage, motorcycle luggage, racks, touring | Ventura - I've been using Ventura racks for 30 odd years now (They're a NZ company) - with no problems. Had one on my SL since it was new. They do a nice pack system (number of designs) for their racks too.
One advantage of the taller rack - is that you can strap your tent to it vertically - and keep the bike nice and narrow. I find that having it across horizontally means it tends to get caught on things from time to time.
Errr - here's the US on-line shopping site - http://www.ventura-mca.com/
