Custom PC Watercooling and Fan control system. Fan control help?

Sparkfun states that FQP30N06L is interchangeable with RFP30N06LE. Just ensuring this is true. They seem to be functionally identical for my purposes as far as I can tell, but so does FQP27P06. I know that FQP30N06L and RFP30N06LE are N-Channel MOSFETs and the other one is a P-Channel MOSFET. how does this affect my project or does it?