The big positive output wire is not the "one wire." Regardless of what alternator you get, you will always need a field wire. You can technically take a regular SI or CS alternator and move the sense wire back to the big positive output post. You lose the remote sense ability, but if you're not concerned about that it won't be a big deal.
There are plenty of one-wire SI alternators out there. I don't have any particular recommendations handy, but they are out there.
Is there a specific reason you want to run a one-wire?
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank