MH is much much more powerful than PC. Some people do great with just PC lighting because they just keep lower lighting corals like softies and LPS corals. If you want clams and SPS corals IMO you should go with MH, but you can do some montiporas with high-VHO lights.
MH lighting is really expensive, so if you don't have the money now, then you should just stick with softies and LPS corals with the PC lights. The SPS corals cost a lot too. 2 or 4x65 watt PC bulbs would be nice for a 55 gallon IMO.
BTW, turn off caps lock, a little hard on the eyes and it feels like you are yelling.