while i agree that a mechanical oil pressure gauge is a good investment, it isnt going to do any more to prevent catastrophic engine damage than the factory gauge. in this case, its not a question of gauge accuracy, its a question of catching the low oil pressure situation before its too late...which isnt long when driving at highway speeds. if your that terrified, a big red light or a buzzer to indicate low oil pressure would be more effective.
a cam syncro failure is somewhat of a snowball effect. the bushing that supports the syncro shaft doesnt receive sufficient lube, which causes it to dry out and wear. as the bushing wears, it allows the syncro shaft to "wobble". once this wobble gets bad enough, it makes it possible for the flag on the end of the syncro shaft to contact the cam sensor...this stops the shaft suddenly which causes the roll pin holding the distributor gear to the shaft to shear off, thus the syncro shaft (and hence the oil pump) stops turning. if you were really adamant about it, you could pull the sensor off every once in a while and spray some sort of lube down the syncro shaft.
as for the oil pressure gauge: theres only one pressure port on this block, its behind the passenger side head. if you want to keep your factory gauge working, you need to purchase a "T" fitting. you simply unscrew the stock sender, screw in the T, and install the mechanical gauge sender in one side and the stock sender in the other. heres a few pics of mine: