In the future I would like to have a garage be 48' wide 70' deep and 16' tall ceiling. The exterior would have 2 double doors for the front be 18' wide by 14' tall. On the left side of the garage would have 2 single doors be 12' wide and 14' tall. Their would be 2 entry door on the same side as the single doors. The one on the the left side of the single doors that is 2' 6" from the back of garage. The other one at the other end of the garage like 2' 6" from the front of garage. The garage would be insulated, heated, and air conditioned. To have of course flouresent shop lights, light switches, dual plug outlets, and the floor in expoy. The outside would have lights above the garage doors and entry doors. The roof pitch would be 4/12. The walls painted white. The only windows would be on the garage doors. No windows on the building itself or on entry doors. For future needs 4 cars and my 25' Baja. Future wife and min daily driver. Two fun cars Porsche 911 Turbo and Ferrari 360 Modena. If I ever wanted to up grade to a bigger boat I could with room to spare. Next boat to be 30 to 35' with a notched transom and a fairing. I could still hook up the boat to the truck in the garage. I forgot to say I would attach the garage to a one story house under 2000 sq. ft. This way I don't have to go outside and I have a smaller yard to deal with.

Alot

That's not a garage that's a warehouse.

Turnkey; all you do is stroke checks: probably $100K rough estimate given what you describe.
There are several threads here on OSO with barn and pole frame construction companies to look into.
www.nationalbarn.com
www.pioneerpolebuildings.com (constructed mine)
www.fbibuildings.com/

for that big a span you should look at steel frame I beam buildings. contact Paradox on here I got a lot of good info for a future build

Warehouse Hell, that's a hanger!
I say that - I put up a 40' x 50' Mueller building and regret not building it bigger.
Waaaay too many toys.

You can save quite a bit by doing things like insulation and drywall yourself, but you will definitely put a hurt on your wallet for that big of a garage. Good luck and post pics when she gets built!!

I'd do wirsbo or some sort of heated floor system we have it in our shop here in MN (damn cold) and I work in a t-shirt and sweat in January , also forced air system hardly runs

i have a 50 x 60 and in the day it cost 40 k to build,,we built another one 42 x 72 and that one wat around 60 k when it was all said and done..

i think goodyear has a few of their old airship hangars for sale, that would be the ticket... build a house inside it suspended from the ceiling, above your toy collection....