You'll laugh at me for this. I bought a Metal Building from Eagle Carports, Inc. I gave them the all the diamentions and they got it for me. I built 4 stalls and a walk way with room to spare for them to come in out of the weather.
The building cost me 2.562.90 delivered and installed. The cost for the post and wood for the stalls cost $200.00 at Southerlands.
But if you want to install your own barn you can go to
Priefert Ranch Equipment
Great site and great barns. or call them at. 800-527-8616.