Hey, what you wear under yer kilt, er, leathers, is your business unless I can benefit from knowing. Then it becomes "technical."
The kayakers in these mountains use a polypropylene weave called 'capalene' which is ideal under either leathers or the textile riding suits. And there is no substitute for the gerbings electrics in temperatures below 50*F. Riding under 38*F you need rolling tire warmers as well.