In my experience bike engines, especially turbo bike engines are no use as the power deliverly is too high and very on off with little torque. i would be tempted with the likes of an alloy unit like the v-tech or duratec IMO, on throttle bodies and aftermarket management for sure. it kinda ruins the drivability and handling charecteristics of a kit car by putting a heavy engine/ big power turbo engine in IMO.