I've got one of these off Andy Francis if you don't want the offset type that fits to the normal sprint rack hole this one fits on the back 2 and then the rear legs fit behind the number plate
http://www.ekmpowershop12.com/ekmps/sho ... 1615-p.asp you can fit quite a bit on it,but saying that I am using panniers with it this year as doing a lot more camping than B&B'ing.Also to my mind if you want to put a bit on it these are more sturdy as you have the rear legs to support the weight,where as the off set type all the weight is on the 2 back bolts,but I suppose its down to personal preference.

I am playing all the right notes, but not necessarily in the right order.