BlueSeal8 customised a VFC Avalon AEG with a Giessele Rail and powered by HPA. He lists all the accessories he used on this custom work... "Here's my new(ish) VFC (Vega Force Company) 416 Avalon AEG with a Geissele rail for 2020. Inside I've got a Redline N7 HPA unit with an Amped Airsoft line.

Here is a list of attachments (all replica):

BlueSeal8 gives us a quick overview of the KAC Airsoft Suppressor which he says works best with HPA powered airsoft guns... "This is an overview of the 5KU brand Knight's Armament Suppressor. I bought this suppressor a long time ago, and I realized there weren't any extensive overviews of this specific model. It is foam filled, so if you run a HPA (high-pressure air) airsoft gun, it can silence your shots!