Blythe

I have been building computers for use as a digital, closed circuit TV, recorder. I purchase the case, often Enermax brand, with power supply. Today, I was called to a job where the computer had been operating for about 18 months, non-stop. For no apparent reason, the power supply was "dead". The system was connected to a good quallity UPS back up supply. Should I consider purchasing my power supply seperately from the case, in order to possible obtain a better power supply? If so, what is considered the "Best" supply to purchase? My big concern is the fact that I had to drive over 200 miles, round-trip, and 6 hours time to replace this defective supply. I have 20 other computers in the field, and adding to the list each month. Thank you very much for your suggestions.