I can say, DO NOT use Stainless Brushes in a Stainless Barrel! I'm not sure about stainless brushes in Chromoly Steel barrels, as I have no experience with that. Bronze is really about the best brush bristle material there is, just be careful with the Bronze if they have a Core made of something other than brass.
I prefer to use the Nylon/Polymer and rely more on the Solvent...That's just my personal preference... And, if I'm not mistaken, harsh solvents like Sweets 7.62 and Barnes CR-10 can harm the bronze and brass bristle brushes, but that's Hear-Say, although from a reliable source.
As for the Patches, I've read that You shouldn't use patches made of Paper, because some people say it'll scratch, but again, I'm not sure about that. I can say, that most of the Synthetic Patches I've used have done great, and I have not read anything against the use of them.