Chevy Astro or equivalent GM. Stopped making them in 2005, but will run many miles (I saw some with 575,000 miles when I was looking for mine). They aren't fancy and don't get great gas mileage (about 18 everywhere, but I did get as much as 23 in one I had years ago). Full frame and rear wheel drive. Parts easy to come by and you can probably pick one up for less than $10,000.
Mine is a 2003 with 52,000 miles and does absolutely everything - hauls kids + friends, mountain bikes (inside or out) plus camping gear and friends, sheet of plywood (seats need to be all the way up), and I sleep in it when I want to camp off the ground.
Another option is the Toyota Sequoia. Not great gas mileage, but I picked up a beautiful 2006 with 48,000 miles for $18,000. Great ride and easily a 300,000 mile motor. Get a 207 or earlier. 2008 was a new model and you'll pay much more (for more than you need).