I know there are cranks available but long cage rear derailleurs and shifters for a triple are gone. Shimano makes Tiagra, SRAM and Campagnolo have abandoned it. Plus Shimano front derailleurs seem to work best with a 53T big ring. Their MTB fronts are not compatible with road shifters. I am not interested in barcons for this build. Sadly I seem to be SOL.
When I built up my rando bike five years ago, I was not sure what to use for a front shifter. As a temporary measure, I used a vintage friction downtube shifter, but now five years later that temporary measure is starting to look very permanent. They work with all bottom pull derailleurs.
Regarding long cage rear derailleurs, there are tons of used ones. I like the look of the 1990s vintage XT rear derailleurs, have them on several bikes plus a few spares on the shelf. Pick something that looks nice, check to see what the cable pull ratio is on it and try it if the math looks good.
Science Behind the Magic | Drivetrain Compatibility ? Art's SLO Cyclery
Jtek adapters can be used to change cable pull ratios if you are trying to mix and match.