Hi Scott,
There's some good info on creating a rack in the Adventure Motorcycling Handbook (
www.adventure-motorcycling.com). If you don't have a copy already, you might want to pick one up.
I don't know anyone who makes a rack off hand, but David Lambeth Engineering seems to specialize in setting up Teneres, so I'm sure he could tell you everything you'd need to know and more.
(from elsewhere on this site):
"David Lambeth Engineering
(Tel: +44 1892 668280 Fax: +44 1892 611883)
in the UK say they have fully prepared XT600Es and Teneres for hire for overlanding."
Best of luck,
Wright Bagwell
------------------
Wright Bagwell
http://www.geocities.com/wwbagwell/