I have been extremely happy with APhotoFolio. Before committing to them I made use of the free trials most companies offer, which I would highly recommend as you can check out their designs, features and backend that way. I liked several of them, but chose APhotoFolio because they were the only ones at the time supporting the iPad. They just introduced a Flash/HTML5 update, so they are committed to the latest technology.
Going the Wordpress route is fine, but you might end up spending more time fiddling with your website than doing your job. Photoshelter is great if you are planning on using your website to sell photos or to deliver images to your clients. It's portfolio capabilities were not great when I looked at it, but that might have changed.