TorqStorm Supercharger build advice needed

I think the fuel injection is the best way to go.
I am not aware of a "stock" forged replacement piston for the slant. I used to use the old TRW L2125F or Sealed Power 1941PX, but they have been long discontinued. I still have a set of .040 and .060 on hand, but they are for my engines. The .040 for my turbo 170, and the .060 for a nitrous motor.