Busse as far as I know make up marketing names for their materials. Resiprene c is from handling it similar to kraton so maybe start with companies that use that.
I think when you start looking a whole new confusing world of rubber will open up. I'd keep it simple and use horse stall mat, I have also seen the matting material used in ramps and speed bump applications so it is available in bits more conducive to through tang projects.