I have 4, 9,000 Ammco lifts 1 with the 36 inch extension, they lift 90 % of the trucks we work on, some of the service trucks loaded with equipment can lift only a couple feet off the ground. So spend the extra and get the 10,000 lb hoist.
I did have to prep the floor, it was only 3 inches thick, cutting out a section 24 x 36 x 15 inches deep for each post.
Than pounded rebar 15 inches under the existing floor, 2 on each end ,3 on each side.
Then a simular pattern a couple inches up from the 5/8 minus rock in bottom of the holes, followed by rebar tied to the previous bars. Filled the holes with 3500 psi rated concrete.
After a couple days set up time I assembled the hoist, squared it the bay door drilled holes and used 8 inch anchors. Don't remember, I think they are 5/8 ".