I got a 6 ton SUV jack ($90) from Sam's club 6 years ago and while it ain't no lightweight I can depend on it to lift a trailer loaded with a car in order to change a flat. Also use it for general lifting around the garage. I also have an aluminum racing loboy floorjack ($150) rated at 1.5 tons, not as strong as the other one obviously, but light enough to throw in my Mullins and will get under some very low body areas where a regular jack just won't go.

Some company sells one that is a scissors type in a box. Pretty pricey but certainly necessary for getting some cars up off the ground. It's usually advertised in Street Scene, Street Rodder, etc. Don't know what the lifting capacity is, but it is designed for street rod use.