Raykos- I did a garage a few years back; not for my tractor (didn't yet have it!), but I went with a local lumber yard/prefab company. It was cheaper by far! Used trusses, but with an attic space; I also specified I wanted NO poles in the center.
Garage is 32 x 32, permanent stairs in the back left. Attic space was floored in the center only, so I purcahsed my own matching flooring, ripped it down the center, added sister boards to joists, notched for truss pieces, and slid them into the space under the eaves. Gained tons of floor storage space between the trusses.
With pre-fab walls, the thing went up (once the slab was done) in a couple of days. I also felt the price was great. Only thing I wish I had done was to put a good amount of insulation under the slab- from one who now has to live with it, don't skip that detail!
Garage is 32 x 32, permanent stairs in the back left. Attic space was floored in the center only, so I purcahsed my own matching flooring, ripped it down the center, added sister boards to joists, notched for truss pieces, and slid them into the space under the eaves. Gained tons of floor storage space between the trusses.
With pre-fab walls, the thing went up (once the slab was done) in a couple of days. I also felt the price was great. Only thing I wish I had done was to put a good amount of insulation under the slab- from one who now has to live with it, don't skip that detail!