Usually when a water pump is going out there is a little leakage from a drainage hole on the bottom of the pump in a direct line with the pump shaft. This indicates a bad internal seal. Unless you have a very hot runnin li'l monster, a stock replacement pump from any well known car parts place will do. If your gasket were the pump contacts the engine you have to pull the pump anyway so replace the pump at the same time. Very inexpensive. If the mods are an advantage for you and you see them as a good value, see the previous reply. Of course, don't forget to flush your cooling system at recommended intervals and put in the correct amount of coolant. Too much coolant causes problems, also.
about your check engine light, hmm, may not be related. I don't believe that overheating will make your check engine light come.