Upgrading 67-72 trucks AC systems to 134a

[TransMan1972]

Is there a place on this forum that directs a person to the DO's and Don'ts on upgrading AC systems on 1967 to 1972 c10 trucks ? I see several posts, but nothing that outlines the right way to do such upgrades without spending thousands of dollars... I read on here several transmission rebuilding ideas and saving money by folks wanting to rebuild there own transmission but nothing on AC systems....
items like :
A6 compressor vs Sanden Compressor
Stock condenser vs after market condensers (Why add a electric fan?)
Use the stock POA valve, how to calibrate it for 134a ? Show the Steps on exactly how to do this upgrade on a stock POA valve. how do I get to 25 PSI...
Expansion Valve....low pressure does not change based on engine RPM ? How do I test a Expansion valve....should I put it in the freezer ?

I could go on and on but I do not want to create this monster if one already exists....