We pull our 25' Safari with a 2005 Express van 3500. You've no doubt discovered the super flexibility of using a full-sized van as a tow vehicle:
oodles of space for people and stuff in the van, good visibility, excellent value when compared to SUV prices.
We usually travel with one bench seat installed for our dogs - just high enough for them to see out, and the back two bench seats removed and stored at home. We put the travel boxes there: emergency box with jumper cables, tow strap, flares, snow chains, multimeter, quick fix equipment, etc.; campsite box with stuff that goes right out into the campsite: table cover, lantern, trash bags, etc.
The van also carries chairs, generator, firewood, water jugs, backup gas can (there's also a backup gas can in the trailer,) compressor/battery jumper (nifty tool!) and one set of clothes.
At home the van is the go-to vehicle for out-of-town family events. We take the extended family and friends everywhere.
I recommend you search for a used 12-passenger van (don't get a 15 passenger van, the extra length is a detriment to towing and handling.) There are many available, retired from schools, rental angencies and van-pool organizations. They have had good maintenance and generally light use, rarely used as tow vehicles.
Here's a review:Chevrolet Express Van Review - Edmunds.com
The 3500 (one-ton) Express has 10,000# capacity. We get 12-15 mpg while not towing, and 9-11 mpg while towing.