Just a note about the 2 ram hoists..If you do go that route, the 1 thing you have to always remember:
When raising the bed/box you have to be on flat ground or you'll tip it over..The 2 ram hoists don't have the sideways play that a single ram has...
And here's a source for a hoist kit:
surpluscenter.com
Good prices, and good to do business with
Geoff