From a guy who bought a chevy conversion van to sleep in and pull with, I offer my comments...
I would not do this again. I bought the 1/2 ton fullsize van with the 5.7L V8. It didn't have a tow package on it, but I was towing a small 5x8 trailer.
It runs great, fits us great (me, wife, 2 kids & a dog) for travelling, but SUCKS for sleeping.
I just bought a new 7x23 trailer which will be sectioned into living and garage so I can comfortably camp instead of sleeping in the van.
Now I have to worry about towing... I just put in a new transmission cooler (this weekend), and the electric brake controls.
I'm a bit concerned about the life of the transmission with towing around 5k lbs of trailer with gear.
The van is great for lugging the kids places in great comfort, but for towing and for race purposes, I'd MUCH rather have a 3/4 or full-ton 4 door truck.
If I were to buy right now, I'd buy a 2wd 4dr F350 diesel. But that's just me... (and my rich wishes)
If you have more than 1-2 people sleeping in the van, you won't have room. Find a truck...