Vir, this topic was discussed often on nano-reef (RSM specific). Some(like me) kept it save with just zoas and lps. I think you can do RBTA assuming you'll feed it 3-4times a week.
Others were able to keep light SPS. The debate was whether the lights were PC or T-5(Red sea calls them T-5 cause of the diameter of the bulb and pin. However, its factory "Custom made", so i felt skeptical when they say you MUST buy their factory ones.)
If you're going light sps, place them up really high. I would not do Clams.