Well, you have enough light to keep most anything you like so you have no restrictions there. If you like flowy corals I would suggest some LPS
ones, such as a torch, frogspawn or duncans. Check out Aquarium Fish: Tropical Freshwater Fish and Saltwater Fish for Home Aquariums
and see what tickles your fancy. Most times these corals are not very expensive and make a great addition to any tank.
For color you can start with mushrooms and zooanthids, they come in every color of the rainbow and can be very very cheap. They are really easy to care for and are hardy in most water conditions. The same is about true for LPS
corals, they might be a bit more finicky about water quality but overall they are easy to keep.
That website has soo soo many corals your head will spin with the choices. What i did was figure out what I liked from the site and then I go hunting for it in stores that are local. If worse comes to worst I will order it online but nothing beats actually getting one that you can pick out and see in person.