I certainly wouldn't store a car on a two-post lift for a long period. Even when I'm working on a car for more than one day, I lower it down close to the floor. My two-post lift is an asymmetrical one from Challenger, which is owned by the company I worked for. Even with my discount, it was a bit more than consumer lifts. I also have two 4-post lifts from Advantage lifts. They are very nice. They came with a rolling jack tray where you could jack the car up to take the wheels off. You still have plenty of access to the bottom of the car for oil changes and other underneath services. There are lots of accessories available for these lifts as well. If you intend to work on a car on a 4-post lift. Get one long enough so that you have full access to the wheels.
Nick