Well I can say is DO NOT even attempt Poughkeepsie Gulch road. Trust me on that, even the SXS guys don't do that one for the most part. Things are getting torn up by the SXS crowd and it will be busy on any weekend with the rentals and such. Stony Pass down to Pole Creek and over to Beartown is kind of cool. Good 4x4 road. Lower part of Engineer is a challenge too heading to US550 so just stay on the upper part.
A nice loop would be from Silverton north on Cement Creek road up past Gladstone to Hurricane Pass then up California Pass and down to Animas Forks. Rocky, so lower the pressure in your tires.
Picauyne Gulch (sp) is a neat loop too but not sure what direction in a van. Kind of dicey on the south connection to the road to Animas Forks from Silverton...
All things being equal - fat people use more soap.