ARES Remington MS-338

[Driver X]

So here's the thing: I recently purchased the new MS-338 made by ARES and after reading some reviews on ASC I found out the piston has to be changed, otherwise the gun will start slam firing really soon. I'm thinking about going with a metal piston and I know the gun is mostly VSR-10 compatible, but I want to make sure the piston I'll choose fits well in the cylinder and is compatible with the trigger (45° sear if I recall correctly). Can you guys help me out? And should I also change the spring guide?