I wouldn't discount the use of an R8 based on experience with an FM. I'm not sure about more recent models, which I haven't used, but earlier R model SLRs had a cam driven mirror that slowed to a stop at the top of the cycle and didn't have the impact against the body like most SLR designs, so mirror impact and noise are both mitigated relative to most other SLRs. Perhaps an R8 user can chime in here on the mirror issue.
In suggesting other starter RF cameras for testing the waters, I'd also mention the Cosina Voigtlander Bessa models and their lenses. These are compatible with Leica screw mount and/or M mount cameras and lenses and would serve as a second film or backup body after purchasing a Leica M if you decide to go that way. There are a number of models available, new or discontinued, at a wide variety of price points with different features. cameraquest.com has articles on the various models and lenses. People compare many of the lenses favorably with older vintage Leica lenses, especially at the prices they go for.