Im with Rowan and others. Brooks B17. I've toured cross country, and lots of smaller stuff, and the leather just conforms to you. I understand trying to stay away from leather (well I don't "understand" but I won't be the one to give you guff for your choices!) BUT, sometimes you have to listen to what works for others and see if it can work into your lifestyle. Call it Flexitarian! I can't imagine being on an uncomfortable bike ride for such a long distance and for that duration. Good luck with the C series Brooks. I hope that it works well for you!