I only have a BSc; but here's some info. I'm leaning towards having the door hinges "formed" to reduce the chance of sagging. Grant also has the formed hinges, but I'm going with larger doors and need longer than 36"
I got my SS hinges right off the shelf at lowes they are the 30" hinges. I used one for each door and two for the hatch and an inner tube under it to keep the water out works fine so far. Just another way to go. Good luck.