I would do a double door since making it taller will require a lot more work since the header will need to be redone

Do you need two door width for those entering/exiting? Then wouldn't choose two doors.

Would not make the door itself wider but you could use a fixed window above door. You could use a standard door (about 3' wide) and add wide sidelights -- whatever the width you need to add any additional light you want to the space and still use a "substantial" looking door: just choose a heavy wood door and sidelights and frame and finish it with the wood look..