I have 2 seat posts in mind: 1) A Thudbuster from Thor (weighs similar to the stock Swift one!) for those touring-just-riding days, and 2) a 27.2 lightweight in a shim, probably a Thomson as caotropheus suggests. I understand they are uber-stiff and you get them in set-back options, something I need if I want to live out my aero posture dream on the go-fast days. Each option will have its own saddle as well, a B17 with the thudbuster and some ass hatchet job with Ti rails for the go-fast.