Cool thanks for the info.
I agree with JN2Wheels that the RS10s should be fine (burly and pretty reliable). I think for this setup, you should probably just go the Shimano route since they seem to be spare parts, and I think it would be a pain to keep switching groups between bikes (I'm assuming you want the nicer stuff on your road bike since you're more of a roadie). I've seen people race in mud with Powertaps so it probably isn't too much of an issue, but I would just ride the RS10s and have some peace of mind. Again, the you're definitely going to have a weight penalty with this stuff compared to your Campy parts, but since you're still relatively new, just use what you have and see if you even like it (you can always upgrade later).
For cranks, you could just use your spare compact Campy cranks and get the adequate chainrings (not sure how you feel about mix and match groups on a bike though...). These days, however, manufacturers make smaller chainrings for 130BCD cranks. Thorne makes a 44t outer and 38t inner that may work for you (http://www.cyclocrossworld.com/cyclocro ... ngs-guards
), that way you could just use your FSA cranks.
I'm not sure you could sell off your old Shimano components for enough money to get a reasonable entry bike (I'm pretty biased though as I highly prefer to spec everything myself rather than getting a mediocre prebuilt package).
Kona's are pretty solid, I saw a JTS yesterday at a race and they guy seemed pretty happy with it. Do you have a price point in mind for the frame? That would probably help us give some input on what other options you might have.