i would go with t-5 tek light, it will not over heat your tank and wont coast you an arm and a leg in your electric bill. i use an 8 bulb t-5 tek light over my 120 and i keep sps and clams with no problem. and you get to play with the bulbs a little so it will have a different look.
It's all about the reflectors.so 4 bulb should be ok for my tank.. what is the big diffrence in t5 and pc's i coulnt tell the diffrence