CYMA or E1 and toss in a Guarder FTK if you really want. CYMA and E1 tolerances may be a bit off spec so with an FTK you might have to shave things down here and there to fit them.
The M14 hop up system is actually pretty genius so it should outrange most other stock guns (and even some slightly upgraded ones).
G&G and CA make a weird V7 hybrid thing that's not really "TM compatible" so I would avoid them but out of the box they're not bad.
G&P is also not bad BUT the problem with them is their shitty internal quality (great externals but shitty innards, it's like putting a shitty off spec POS engine into a Ferrari). Honestly with what's out there right now (VFC, KA, Lonex) I can't really recommend G&P anymore.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE