Hi and nope, none of the above. It's a clone of the Tokyo Marui AEPs and will take those parts.
https://eagle6.co.uk/shop/parts-upgrade-s/internal-parts-upgrade-s/int-aep-tokyo-marui-electric-pistol-aep-series.html
The first thing I'd suggest is wiring it to take lipos:
http://crapworks.blogspot.com/2013/04/airsoft-glock-18c-nimh-to-lipo.html
The difference in both
semi auto response and RoF is significant, and it's also pretty much a pre-requisite to the other big improvement, an upgraded spring which should bring it up from ~200fps to 260fps+.
https://eagle6.co.uk/shop/catalog/product/view/id/206/s/eagle6-airsoft-upgrade-spring-for-aep-cmg-series/
You might consider swapping the stock nylon bushings out for Laylax bushings, although I seem to have just bought the last set from Eagle6. Probably not critical, that's more of a longevity issue.
I'm running the stock barrel and rubber, although I've flat hopped it and am using good old pencil eraser as a nub. It's fairly consistent, at least for CQB purposes.