Direct Induction PK XL



I have managed to buy a direkt induction PK50 XL. Problem is that I need a new piston (as previous owner destroyed it by playing) and they are apparently not the same as the normal induction piston and appear to be unavailable ????? Does anyone know any kits/upgrades that support direct induction (ie induction is on the cylinder not the crank case). I understand the crank is different and not machined induction port on crankcase. 

Any thoughts even if where to buy a new 50 piston