I agree that you need not go past the 1980s for an affordable lens. I have been shooting a Fuji 150 6.3 since 1986. Still sharp, still accurate (Seiko shutter).
To start, stay with plastic film holders, check the slides for light leaks. Clean everything extremely well. While I have used trays, the absolute darkness is always concern. I use System 4 tanks with home made nylon screen tubes and process the sheets just like 135 or 120 film.
Take is slow and work everything through. Write EVERYTHING down and make repeatable systems.
tim in san jose