Forget about the Dendronephthyas unless you're willing to put in a lot of research, time, and money into food and equipment. Some people have had success, but they have setups that are specifically designed for such. It's not impossible, but Dendronephthyas are definitely not the kind of coral you just add to any tank, especially if this is your first foray into non-photo corals.
Sun corals are one of the best starter non-photo corals, next to Dendrophyllia. If you take care to feed them regularly (once a day or once every other day) and keep the tank well-maintained, they really are pretty easy. Dendrophyllia are even easier and don't seem to need as frequent feedings. Chili corals seem to be pretty fussy, specifically about flow. I would not personally recommend them, but I haven't really ever tried them, so perhaps someone else could chime in on that one. There are a few non-photo sea fans/gorgonians that have large polyps that aren't too difficult. Swiftia sp., Diodogorgia sp., and Menella sp. are some examples. The one key thing that I've found with non-photo sea fans, however, is that algae can be a real killer. You need good flow on them to keep them free from algae, but even really strong flow can be insufficient. The best thing for them is to keep them in the dark with good flow.
