or as an alternative bike that lets you put your feet down at a stop without getting off the seat, there is the Rans HammerTruck:
how 'bout 160 lbs of salt:
not bad!
The only real downside is that it's pricier than a Big Dummy and is harder to find in stores. $1995 in stock spec (bare rack only) with a 525 lb rider+cargo weight limit. EDIT: whoa, the stock Big Dummy is $2450 with a weight limit of 400 lbs. Well, once you add the runners, top plate, and such to the HammerTruck it's pretty close to Big Dummy prices.