Looking for planning help for polebarn style workshop to be built in the spring

[DeadheadNM]

Hello:

Starting to plan for a workshop to be built on my property come spring. I've never had a building built so appreciate any advice that might help me get a good result. I'm anticipating a concrete floor polebarn style building large enough to easily accommodate a 2x2 arrangement of four longbed pickups (two front to back).

The location on my property (pics below) seems best suited to something deeper than wide. The site (and whole property) are on a gentle sloping hill so the site will need some excavation and I assume retaining walls.

Any advice from contractor selection, materials, door types, etc.? Would a 30x40x12 building be large enough to have four trucks with room for working and storage?

Thanks, Pete