I have just noticed this thread. Hope my reply comes in time.
I built mine much like you are thinking about except i have two doors in the rear, left/right.
If i had to do it over again for the same reasons, I would not change much just the details.
I will get more pics in my album when i can. Just had my right shoulder operated on so am a bit more handicapped than normal.
I tow mine on gravel, dusty, no roads, almost 1000 miles of them in the past 2 years. I have gotten the dust seal to where it is very livable.
The right door has a counter on it now and the left one will get one before spring time. I hope. In the center they interlock with a seal. On the bottom there is a bolt latch with an iron bar i made to operate it. Also a hole in the bottom of the bolt cut out so i can open it with a #2 phillips screw driver or similar tool with the rod breaks off. I made the central counter top to close to the doors to reach in with my hand. Then i added a 1/4 inch bolt and T nut on the top to draw them tight up there, doesn't take very long to operate.
I used 2 house door hinges on each door, screwed into oak, rated at 50# each hinge so 100 # total. I would see if i could find some stainless steel hinges as house door hinges are made to be inside. It will be constant oiling for me.
Will get more pics in the album as i can. New pics might be a few days,