Here is an 'off the wall' solution but it will work in your situation. Skip the door frame, cover the framing and rough edges of the drywall with aluminum coil stock bent an inch or so on each side to cover the face of the opening. Now, add a 1/2" door stop to the sides and top, get a 30" 3 lite panel door of wood (no fiber materials like masonite), rip an inch off each side of the door to make it fit the opening and do a normal hinge and lock with an aluminum threshold. The top will need to be filled in to give you an 81" height.
Then, if you want a storm door, it will have to be custom made for the opening. I would recommend the storm door in your climate.