Be sure the floor where you plan to install it is rigid enough to handle the load, even if you have to dig deeper and pour a thicker slab in places. Then figure out what capacity and height of lift you want, and go at least one size bigger in both dimensions. Nobody ever regrets upsizing capacity, assuming the shop where you're installing the lift will accomodate the upgrade. My shop has a 6" steel reinforced concrete floor slab and 12 foot walls, so I'm planning to go with a 10K pound capacity lift that lifts the vehicle at least 6 feet off the floor.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!