Which should I buy?

In most instances, used campers of any kind are usually a nightmare of someone else's problems. You can do a search of the web about buying used campers and get an awful lot of info. One thing you have already that is a must in a search of a used camper, is your nose. If it smells musty, damp and has odd odors, walk away. There is probably water damage. Check every corner, open every door and look for stains or signs of repair to walls or floor or to cabinets. Walk around camper testing your weight on the floor looking for soft spots. Check around windows for signs of water entrance and damage. Check the bathroom floor
for water damage. Get up on the roof of the camper and check the caulking, check the roof for soft spots, be careful up there, most roofs don't hold weight well. Check the tires for wear, wheel bearings are hard to look at but it is one of those things you hope is ok. Do your homework and do not buy the first thing you see. Good used campers can be costly in price and repairs if you get a bad one. It may be to your advantage to check the discount RV places, you may very well get a discounted camper at about the price of a used camper.
There are many things to look at when buying new or used so do your homework before you pay for a camper. Good Luck