What else are you expecting from the vehicle other than towing? What other activities are you into? Biking, hiking, kayaking, etc?
We are now a family of 7 and have had our van for two years. I absolutely love it. It does a great job towing our trailer and it is great for non-towing trips. In early April we did spring break in Florida. I actually left half of the rear seat in so the van had seating for 10 and we had plenty of room for everything. We have an infant so we actually had a pack-n-play, stroller and the baby bath with us. If we still had either of our Suburbans we would have been packing on the roof for this latest trip.
My only concern about the van was how it would do in the winter but that has been a non issue. I do put 240-400# of salt in the back, but with the skinny tires, the weight of the van and traction control it has been fine.
I would highly recommend looking for a 2010 or newer GM van as you will get the 6L with the 6 speed. I think in 2013 they started offering the 4.8L, but I would pass on that and go for the 6L. Depending on the size of trailer you are considering you might want to look for a 2500 as the ride should be a little better than the 3500.
Aside from customization, your other non-van options are the 2500 Suburban or the Excursion. If I am not mistaken, the Suburban actually has more payload than the Ex. We had a Suburban for 5 years and it was great, but the versatility of the van outweighs the luxury features of the burb.
