Since you’re going to use the PlayStation SCART cable solely with a PS2, be sure to order it with NO capacitors. The PS1 hardware was designed to have 220uF caps in the cable, and the PS2 changed that by moving those capacitors inside the console; so PS1 cables require 220uF caps, and PS2 cables require no caps. I’m not sure where people got the idea that 1000uF caps were appropriate, but that doesn’t conform to either console’s electrical spec.
I’m not sure what PCB is being referred to, but it’s possible that it’s a bundle with the cable and an RGB bypass board. If you don’t have a SNES Jr./Mini (which only output RF and composite, I think), then you can just get the cable without the PCB. In any case, if you really want to know, email Retro-Access and ask for clarification (and maybe also ask they put that clarification in the product description).