If you have the pump down the well you don't need to put anything over the well. Just run an appropriately rated wire from the barn to the well, sized for minimal voltage drop at the required current. Also bury the water pipe below frost depth. Code dictates a minimum depth for the electrical. Use pitless adapter to bring the water out the side of the well casing at the depth you want to run the pipe. Use nice big black flexable (sort of) pressure pipe. Probably want 1.5" or so. Bigger is better to minimize pressure drop.
Tank and pressure switch go in the barn. Leave drain valves at low points to drain everything. Maybe put something at a high point to let you put in compressed air for blowing out the system with fewer drains. Try to avoid making low points in the plumbing.
When you get the house done you just move everything. Or build a protected space with some backup heat around the tank and pipes in the barn and run more buried pipe.
If someone here would comment on the proper use of a check valve. It would seem useful to have a check valve before the tank and pressure switch rather than have one at the pump. Then a valve on the pump side of the check valve would let water drain back into the well.