I would not do it post by post I would use a plugin so I can manage it more and present them in lightbox or as a gallery. Plus in the future if you want to blog or add news you can always use the posts for that.
Nextgen Gallery has been around for some years and I manage tons of photos and I can export and import pics with no hassle.
The built in wordpress gallery as an option sucks in my opinion.
You should maybe get pixelmine plugin (cost some) if you want to steer away from the gallery look and have albums and such.