I spent about 3 years trying to figure out what lift to buy, and before all else, one question is most important: how tall is your ceiling. You can control almost everything else to some degree, but unless you're going to raise the roof, you can't change the ceiling. If you have a low ceiling, you're pretty much stuck with a max jack, or some other half lift system. I feel like 10' is fine for any lift. 9' is getting kind of close. My co-worker has a four post in his 9' garage and it's pretty tight. Luckily he's into Porsche's and BMWs.
Once you get past this, the important questions are:
-what do you intend to use the lift for? Maintenance only? Storage only? Maintenance and storage?
-what do you know about your concrete? How thick is it; 3", 4", 5"? How strong is it; 2500psi, 3000psi, 3500psi? Does it have rebar in it? Are you willing to have your slab tested or re-poured to get the lift you want?
-what kind of vehicles do you intend to put on it? Short sports cars? Big trucks? Something in between?
-what kind of garage door do you have? How tall is it? Where is the opener? Can you make changes if necessary?
-do you want the lift to be permanent? Temporary? Movable?
For me, the answers all pointed toward a 4 post lift:
-My ceiling is 10'4" and both the DeLorean and my Opel GT can go all the way to the top without issue.
-Being in Florida I knew I likely only had ~2500psi concrete, and I'm sure that even though the slab was supposed to be 4", it likely varied larger and smaller. The 4 post meant I didn't need to anchor to the concrete so the concrete didn't matter.
-I needed to raise my garage door from 7' to ~9' to get the clearance I wanted. Though it wasn't necessarily a requirement, I also changed from a center door opener, to a corner jack-rod opener. This was pretty much a weekend's worth of work to get the door raised, the new opener installed, and everything adjusted accordingly.
-I mostly wanted it for maintenance and didn't think I'd use it for storage. I was wrong. Since I've had the lift, I've never used my second garage bay for cars. I've been amazed at how much bigger it's made my garage feel. I absolutely love having the cars stacked now, rather than parked next to each other.
-I also do quite a bit of maintenance with the lift, so I have the runway jack that runs down the center of the lift that allows you to jack up the car. I also have lift oriented tools now like a lift transmission jack, lift oil/fluid basin, tool cart, etc.
-I couldn't decide exactly where I wanted the lift so the 4 post is great because you can move it with the casters. In fact the first time it was assembled, I decided it needed rotated, so I rolled it from the garage, into the driveway, spun it, and brought it back in the garage.
If I had a dedicated shop with a lot more floor space, chances are I would consider a 2 post as they're geared a bit more for heavy maintenance, but so far I've yet to have any work I couldn't do on my 4 post. This includes a full exhaust rework on the Opel, pulling the transmission twice on the DeLorean, lots of suspension and brake work, about a dozen oil changes, and more. For my home garage, I'd always choose the 4 post.
Lift 0.JPGLift0.JPGLift.jpgLift 2.jpgLift 3.jpgLift 4.jpgLift 5.jpgOpener.JPG
EDIT: On a side note, the distributor for Direct Lift where I bought my lift is in Ft. Meyers. It was about a 3.5hr trip for me to pick up the lift, but it looks like it'd only be about 1.5-2hrs for you.