Northern Tool - (800)533-5545, Part# 144470-C169. The price is $149. I have put it to the test for over two years. It is a little heavy, however, I always take it the track. When you change the rears, you can pick the cross bar junction on either side and lift the whole rear from the one point. It has a 3.5" low side profile. With the rubber jack pad, its about 4.25".
Eastwood (610)323-6269, offers hard rubber jack pads. They come four to a set and they work perfect with any floor jack.