Lots of people have success with pacific anemones such at BTAs and LTAs. They rarely move around, and when they do they don't usually go far, so you can usually keep them on a seperate island away from valuable corals. The main problem you'll have in that case is if the anemone releases from the rock and floats around the tank, landing who knows where. AFAIK, this is relatively rare for pacific anemones, but atlantic's like condylactis are much more prone to moving and releasing. I'd stay away from condys in a reef tank.
TBS, I personally would stay away from all anemones in a reef tank. If you do get a mover, they can cause no end of frustration as they wander the tank spreading destruction. Not only are they a danger to your corals, but to themselves as well, since they have a tendancy to find pump intakes which can result in their death, and possibly crash the tank. A species tank would be much more suitable.
Keep in mind, there are quite a few lps that are pretty close simulations of anemones, such as torch corals and other euphilia, that will give you close to the same look, won't move around, are very hardy, and have a pretty good chance of being chosen as a host by clowns. These are, IMO, much better choices.