Nice!
I have a thought about your centered door placement though. Given the interior width of the center section of ~19 ft., centering the doors leaves ~4 ft. on each side. If you use a 12 ft wide door (10' is on the skinny side) and offset it to one side, you would have a more useful access and width of storage space along the opposite side, about 9 ft.--which is wide enough to store some tractor implements, 60" lawn mower, etc.
A 12 ft. wide door allows you to move some things in and out of the barn without moving a parked tractor or vehicle out of the way too. For example, if the parked vehicle uses 8 ft. of width when tucked in near the outside wall, that leaves a minimum of 4 ft. of clearance between the side of the vehicle and the door opening.
Just something to think about.