I can not complain too much about NAPA. My NAPA place here in town is very well stocked, has usually what I need and the staff is knowledgeable and friendly. I buy many of my parts there, although, most of the time name brands and not the NAPA brand.
One word to the alternators tho...I bought a while back a NAPA rebuild for my Bronco and went through 3 of them in a matter of 4 weeks, all failed because of different reasons, once the regulator, once the bearing making a racket of noise and once the alternator not working to start with because of an interrupted winding. So yes, I agree, rebuilds are a gamble...I gave the NAPA one back and paid up to a new Bosch which is working just wonderful to this day.
So, that was my 3 cents, and I dont think it is necessary a "NAPA rebuilt alternator" problem, but rather a "rebuilt alternator problem. As for the waterpump, I had no experiences with any, so no idea. But yes, I sure was ^&$**#^, that I had to change that thing four times.
Marcus.