L96 Upgrades

Okay guys, so I bought a UTG L96, last year and am just getting into the upgrading. I'm looking for 500 fps consistent with .30s

I have so far:
Firefly Hard Bucking
Prometheus 650mm 6.03 (Decided on the .03 because it's much easier to maintain than the .01)
SCS Nub
PDI Hop-Up Chamber
Laylax Zero Trigger
FF Cylinder head
Polar star silencer adapter
220mm Silencer

I'm going to get:
FF Teflon Cylinder or the PDI Palsonite cylinder. Not sure.
FF 9mm Spring guide
FF Piston head
First Factory PSS2 3 Element Piston

The last thing I'm going to buy of course is the spring. I was looking into the PDI SS 2000, the PDI SS 3000, and the PDI %380.

I'm not sure which can get me what I want. I'd like 500 with .30s but 490-510 is alright too.

Help me out please, and let me know if anything is missing, or if you have any suggestions or criticisms.