Good choice as a BTA is also a natural host for Maroons but you have to deal with splits with them. Sebea can be two species its just a common name for Crispa or Malu. Crispa really prefer to be on the rocks, pretty much attaches like a BTA, foot in a hole or crevice, and is the larger of the two. Malu prefers to be in the sand and is the smaller of the two. They can be a pain to acclimate, so I would try and get some cyproflaxin (also sold as fish flox) just in case you need to treat the anemone. There's a pretty lengthy thread on RC about the treatment and it has had great success.
Crispa has a very fat leathery column.
Malu has a skinny column, sometimes there are rings on the tentacles and few tentacles than a Crispa