i would use a duel axel tandem for that winter trailer. i think it would be more weight balanced then.

i would build my own, but i have no place to build one at the moment; im pretty much living out of a suitcase these days.

i looked at that web site and REALLY liked the rocketeer unit. well done there!

im leaning towards this place: http://www.adventureteardrops.com/
because they are just down the road from where im staying at the moment! $12G for a delux model with a few options!
All it needs now is a roof rack, and solar panel!

al