Here is the only problem I see, you will need at least 14 feet tall for a car lift, you will want it to be 40 feet long or bigger unless you never plan on getting a bigger boat, and 12 feet wide. That is as small as I think you could go for what you want to do. I am building a shop in the next year or so 100x60x25 so I can put all my toy's in and back a 50 boat with the truck hooked up.I dont have a 50 yet but they don't make them much bigger that I would want. Now here is the problem, I have A1 zoning so I can put up pretty much any size garage I want, but depending where you are and zoning you might not be able to build one that big. A lot of the places I was looking at for houses were only letting you have a garage that was 75% of the house size. So make sure you check that before you buy, it would suck to have to tell the wife you have to sell the house a week after you moved in.