[Drakker]

If money was no object and skill was available locally I'd go with a PDI cylinder, a modified PDI cylinder head with sorbo and PDI vacuum piston with the hole plugged with a custom made LONG air brake. I'd keep it G-Spec length and use a 300mm barrel from Laylax or PDI with the bridge removed and an r-hopped. I'd buy the Airsoft Pro hop-up lever arm, file the bump away, install a proper m-nub. The G-Spec has a lot of over volume, which is why it makes it hard to make it silent, but a long air brake and a sorbo fix that problem. The hard part is finding someone to make the air brake, you can't actually buy it in online stores.

Since money is in short supply and local skill is not available, I settled for the PDI cylinder + King Arms piston with a short air brake, but I'm looking into finding a long screw with proper threading to make a custom long air brake that fits the KA piston.