I would stay away from G&G. I would go with either Prometheus or ZCI. The latter being the cheapest and is a really good bang for your buck. Just remember to clean the barrel once you get it.
The only difference really between the regular M14 and the EBR, apart from disassembly, is that the motor housing is different and the EBR takes a long-type motor - instead of the usual short type motors that the regular M14 and Soc16 take.
The only difference between EBR and standard M14 disassembly is the hanguard/body. Once you remove the 6 or so screws at the top of the handguard and take it off, you need to remove the large hex screws on the side of the handguard. 1 on each side. Then it's pretty much a routine m14 disassembly from there (pulling on the trigger guard etc) Start the vid at about 1:28
https://www.youtube.com/watch?v=JK8UsVr4Riw
Some more useful how-to vids for starters
https://www.youtube.com/user/AirsoftingTutorials/videos
Just remember to take your time. 
Lastly you may want to look into a sorbo pad as well.
Sample list:
SHS M14 Nozzle
SHS M14 Cylinder head
Sorbothane pad for the cylinder head
SHS/ZCI high torque motor
Gate mosfets are pretty decent with an M14 in terms of ease of setup (any 3034 based mosfet is good too, like nukefet)
SHS m110 spring (M120 might be too strong maybe)
If you feel the need to upgrade more compression parts:
SHS/Lonex piston head (POM Material)
SHS or Lonex piston, but I think the CYMA is pretty decent
Your cylinder is probably good. If you ever do want to upgrade, make sure it's M14 specific
Barrel group list:
Modify baton ryusoku hop bucking/nub
ZCI 407mm barrel if you don't feel like dishing out money for a prometheus
SHS/Lonex/Guard bearing spring guide