Yes, one-wire replacement alternators should not be hard to find.
My 10 year old 1-wire 12v alternator (between 45-60 amps, but I forget) is wired through the stock 6v ammeter to battery. No problems with the ammeter and no problems with alternator. It is in a 54 truck (12v conversion), so there is no need to have a dash idiot-light.
This truck is not driven far from home.
