I think a class A toyhauler might solve your problems, take a look at this one that recently sold at ppl in Houston http://www.pplmotorhomes.com/diesel/2007-Simba-30874.htm
Simba toyhauler it has a garage with lift in the back that could be used to haul merchandise and convert into a multi function space or bedroom when empty. There is also another bed in the ceiling up front, and a sofa bed in this layout. Then just tow a small car behind for running around.
p.s. PPL's sold list shows the 07 Simba toyhauler sold for $38,500
