Swimming pools

OK, so we're thinking of getting a small above ground pool. There are several options out there making it kind of hard to decide. You have sizes like 12' x 36' or 18' x 48' (do you go big or small), then there is this one

or this one, then where to put it especially when your yard doesn't really have a level spot in it and your husband is wanting to put it on the driveway or patio because that area is level. So, what do you think? Anyone with any experience in any of these options?