I just bought an acrylic 55 and want opinions on VHO or PC lighting. I would like some SPS or clams, if possible. The tank is only 20" high, so I was hoping that if I put them high in the water column that I could house some SPS. However, with these limtations in mind, should I go with PC or VHO to accomplish this? MH are not an option at this point. Please advise.