If you have having multiple alternator failures, you might want to dig into the battery cables, grounds, and load test the battery before throwing another rebuilt at it. The best rebuild in the world isnt going to last long pumping at 100% duty through bad connections and a weak battery all the time.
Any time I replace an alternator I spend as much time cleaning connectors, checking cables and crimps, and checking grounds as I do on the labor replacing the alternator itself. I always use the cheap parts stores alternators and have only had one failure, and since that one went almost as many miles as the factory original, I have a hard time blaming it on the quality of the rebuild.