Thought I would add my 2 cents worth on the chamois discussion. The past couple of years I have been riding without a chamois. Previously I liked the Terry T-shorts, but recently the chamois would just drive me crazy on longer rides. I switched to compression shorts with no chamois (running shorts) and have had no problems, even on centuries. During colder weather I use my Sporthill cross-country pants with long underwear underneath.
Each spring I get some soreness over the sit-bones, but after 2 or 3 rides I seem to have broken my sit-bones in and have no further discomfort.