We bought an 03 Chev full size new a few years ago as a tow veh. I shopped both Ford and GM. The GM vans had a longer wheelbase and a think had 4 wheel disks earlier than the Ford. I heard some stories of Ford drivetrain issues so settled on the GM.

It has been very reliable other than the ign coil on 1 cylinder. In mid-03 GM came out with a 6.0 motor that pulls very well. I also think the GM has a bigger rear door opening than the Ford. Its great having all the space and come in handy moving stuff.

I hate to say you may want to look at new, but I am sure you could also get a deal on one.