Get yourself a Shimano 10 speed RD (other than Tiagra) that will handle the cassette range you want, a rear wheel with a Shimano-compatible freehub (or, if you're lucky a free hub conversion of your current wheel), a shimano cassette of the range you want, and a JTek Shiftmate #3. Don't give up the glory that is Campy 10 Speed Shifters with Ultrashift.