Try
www.mdiracing.com Les should be able to get you rims for your car. You can also use Cross Fireforce rims on the F103. I know those are readily available. Schumacher is importing Cross, so your LHS should easily be able to get them. Don't cut your tires down, just true them and bevel the edges. You want them to be as big of diameter as you can get to compete with the rollout of the "true" Pro-10 cars.