I built my own place in NY, wood frame 2X6 ground floor with a Vault Truss roof that sports a 12X36 foot room upstairs....friends helped lift up the walls to their braces, and a small crane crew was hired to put on the trusses and steel roofing.....did all the rest myself...(had an existing slab and oil pit from an earlier garage that the State tore down)....Nearly killed me though....all things considered, because of the construction, it's a bit more strong and has a higher value than a steel building, BUT to have a steel building put up on your site is a LOT easier, and for car guys, may make more overall sense.......you can get more bang for your buck if you choose the right company.........no termite or dry rot issues, and you can get a bigger building for the same bucks (except for a contractors labor.....)
There are some GREAT deals out there on steel buildings right now.......do your homework before you decide..........If I had it to do over, I'd probably go steel.