I would think you could design a way to install the doors anywhere you want with the Adams Truss building..,,
But that wasn't your question.
I used 6"x 6" pressure treated 18' posts for my 14' sidewalls. End walls had 22 / 24' posts.
Each post was set 3 1/2' deep in a 14" hole. The bottom of the hole had 6" of gravel, and after the posts were set and braced the holes were filled with pre mixed concrete.
After the building was constructed, a gravel base was put in place that surrounds three sides of every post, then a slab was poured on top of the base. Around the exterior, I have the dirt sloping away from the building. It has been up for about 10 years, and it's as solid today as the day I built it.
We have a company that pressure treats lumber 1/2 mile from my building. The only sell wholesale, but was able to set up an account through the business I had at the time and bought all my lumber from them for two thirds the cost of the lumber yard. Their only stipulation was you had to buy a lift or half lift quantity.
I wouldn't shy away from a pole barn...I used 26 gauge metal, and the metal building insulation. From the outside it looks like a metal building.
Of course I would rather of had a true metal building, but this worked for me.
Good luck
Dean