There has been a lot of discussion on barn / pole barn doors and if you don't count looks, then rollup doors seem to be the favorite type of door, for ease of use and small footprint (although it helps to have a powered lift of some type to mount it).
When looks count, and for the kind of barn in your picture (I'd call it 'traditional'), I'd strongly agree that sliding doors are a good fit. I've also seen (in the forums) large swing-out doors, but just my opinion that sliding doors look better.
Sliding door hardware is not too expensive...and not too hard to install (unless like me you have 13 foot tall by 8 foot wide doors two each - took three people and a tractor). Unless they might be blown around violently by the wind you might want to keep the weight down. I used galvanized metal siding on top of a 2 x 4 frame.. turned out to be very heavy they way I over-built it (too much 2 x 4).
Sliding doors have downsides, like being heavy and hard to seal out varmints.