You could keep an eye on ebay, they do pop up now and again, I've watched them go for between £150 - £200. Monsoon 4x4 do them, but they're £300 plus brand new. If by the sensor thing on the dash you mean then clinometer, it's basically to show you what angle you are at, and if you are in any danger of rolling over when you're off road. It also registers heavy acceleration and sharp breaking. As for the dampers, they're supposed to be a 3 stage adjustment, but I oculd never tell the difference when I had mine. Some of the leaf sprung fourtraks had them as well, but the easiest way to get a more civilised ride is to get an indy!! The sporty is great, like a little bumper car and a lot of fun, but not the most comfy vehicle on the road!

Keep on trucking