I would definitely consider the conv. van. as the Tow Vehicle and still tow a Travel Trailer or what ever you want. the minivan can be done, but not with the amount of people you propose. And while tent camping can be fun, I think it will get old real quick after the first month (maybe 1st week).
Here was my setup. I miss the van, very comfortable and towed the trailer effortlessly. took it on a trip out west to Glacier NP with no issues.

We go out with our trailer as often as possible and having tent camped, it is much faster to set up.
BTW, that van was a 97 and had 100k miles on it when I bought it, only paid $3000 for it back in 04. and there was zero problems with it both before and after.