I have a 4 post Rotary Revolution http://www.rotarylift.com/uploadedFi...RFP7000-41.pdf lift in my garage - it's great. Rotary is the same manufacturer that dealerships and auto repair shops typically use.

Benefit of a 2 post lift is you can use it for wheel work.

The benefit of a 4 post is you drive it on and lift it up - no moving the swing arms under and lifting a bit to get alignment and then lifting up to connect and raise the car the whole way.

The downside to the 4 post is that you need to also get jack trays and jackstands if you want to do wheel work.