unless it just for storage or doing alignments, I wouldn't recommend a 4 post either. I've used a ton of different lifts over the years and I highly recommend getting a professional grade lift vs. some backyard type. Make sure the lift is ALI or ETL approved.
I got my Bend Pak 10,000 lb clear floor wide lift from this place a few years ago :
http://www.e-autolifts.com/
good people to work with and there were no hassles at all.