I'm not sure about the corals so I'll leave that part to another. Good hitching posts if you want live stuff would be stuff like shaving brushes, kelp, and sea grass if you can find it. I'm sure I missed some but are the ones that come to me right now.
Zoas might work and I've read some mushrooms. The biggest problem is flow, enough flow for the corals might be too much for the dwarves. The acan and chalices won't work because of the feeder tentacles, because of their size the are very susceptible to stinging corals. Also keep in mind that hydroids are also a problem with live rock since hydroids can also harm or kill a dwarf.