You can't say a clown Won't host something, its all a matter of time, the instinct is there, its whether or not it comes out...Many ocellaris here on RC will host just about anything, PreFilters, overflows, Mag floats. BTA's are often chosen by new hobbiest because of their hardiness, ease of care, and they are the most accepted by most species of clowns. When you get a BTA, make sure it is atleast 3X bigger than the clown.
Due to you having a RSM, I would go with a good old BTA, the rsm has 2 55w PC's not T-5's like they claim. BTA's are hardy and can tolerate lower light levels, I would just make an effort to feed it a little more often. If not once a week, once every 2 weeks would be appropriate.