Brian, does your lighting have individual reflectors or ICR (Individually Contoured Reflectors)? OR, does your lighting have a flat, Parabolic reflector?
Contoured reflectors are the secret, behind successful T5HO lighting, and almost essential.
With contoured reflectors, you can grow any corals you want, but may want to put the highest light demanding corals, highest in the tank.
Easy growing corals, under each category, would be:
Soft Corals
Just about any soft coral you want, though some are aggressive and can quickly take over your tank.
LPS Most LPS will do fine, with your lighting, but here are some of the easier varieties.
Candy Cane
Frogspawn
Hammer Coral
Acans
Echinophillia
SPS. If you have contoured reflectors, the list is quite long. Without contoured reflectors, you'll need to stick to the lower light demanding SPS corals, such as:
Montipora species
Acropora valida
Hydnophora species
Turbinaria
Pocillopora
Seriatapora hystrix
Seriatapora gutata
Stylophora sp
With contoured lighting, you'll be able to keep other Acropora species, but they would do better, higher in the tank.