those are sweet and would be my ultimate build !
i would go with a real deal honda ATC 70 motor with a 4 speed auto clutch and run a 125cc big bore kit with a wizco forged flat top piston and a high comp big valve head with a tall cam and some mid range port work !
i would be looking at a 50-60 mph bike with a 4 speeed auto shifter and more power than one would ever need !
fat dirt track tires would be a must with long travel adjustable shocks !