I own an absurd number of cables from retro console accessories. A few things to point out. Both RCA and RGC were building cables quite some time ago that were cable of damaging the Framemeister, yes both. Those cables have not been in production for a long time and they both have stated that they would replace them for people. It also only affected the Boosted Sync cables, not to be confused with Buffered Sync cables.
Now that being said, I personally get them from RCA because she is US based, builds good quality cables, and they are shielded even for the cheap ones. She also offers the fully shielded cables, just like the RGC guys and she offers metal SCART heads if you want them.
My only personal issues with RGC are that he uses Epoxy or Glue or some shit to "seal" his connections inside the cable and he is UK based, so more expensive for shipping, plus whatever the conversion rate is at the time. I do like his circuit boards though.
My last little bit, RCA has a website. She has had it up for a few months. Stop buying the cables on ebay.
http://www.retro-access.comShe sells more cables, with more options, and cheaper if you just go through the web page. Screw ebay and their nonsense.