I can't speak for the availability and cost of different options.
We owned a house that has a master bedroom and bathroom that were open to each other, all one room. What in the world the former owner was thinking, I will never know. We put in two french doors, oak, and stained them to match our woodwork. We put sheer curtains on the doors.
We hung them ourselves and it was fairly easy. From what I know about installing exterior double doors, the particular model could be anything from very easy to very difficult to install. Some doors come as one assembled unit and you just pop the thing in place and screw it in. Others come in multiple parts and you have to assemble the whole thing in place.
If it was me personally, I like french doors on a dining room/office type room, so I'd go for whatever you want long term.foe me that would be real wood, not mdf. And I'd try to get them the size of the full opening to keep it open and light. If not the full height of doors, you could put a transom over it.