JG G36 CQB build?

Alright guys I need some help here. I just tackled my first gearbox fix on my M4 and im feeling brave. Ive had a JG g36 that has been a really fun little bush gun that I loan out alot and have been running a 11.1 lipo in that broke. I know I know thats way too much battery for the gun but I don't care it was a super cheap gun and it doesn't bother me when shit breaks it just gives me a chance to learn more when I fix them.

So the question is. How can I build this gun into a high rate of fire cqb beast. I would like suggestions on what fps to build to and which parts to use including brands? I want to put the best barrel in it I can and a real good hop up and bucking. But the main goal here is ROF I love those videos you see on youtube and guys are just sending a ton of bbs flying in short quick bursts. How do I get to that point?