My buddy was installing a four poster in his new house/garage today. He mostly did it for parking space, but he told me it has jack adapters on the inside of each rail so you can use the jack points and take off the wheels as well, which is my only problem with a 4 post rail lift.
The school surpluses their lifts from time to time. Some of their older ones are a big, flat scissor lift, which would be perfect for the flat-bottomed Spyder. Last ones they got rid of went for $300.