[mateba]

I need some help with upgrades, if anyone can lend their opinion on a durable upgrade to increase ROF i would more than appreciate it.
Over the past five years I have been purchasing equipment without much regard to role limitations. After buying a c-mag recently, I have joined a state wide team and instead of waisting the c-mag I have decided to conform to the characteristics of my weapon's role. I run a SAW, this is my setup:
TM GS SG/1
Hero 3000 round C-MAG (pressure switch)
EG-700
SystemA m110 (well used, shooting around the 350s)
8.4v 1700mah NI-CD
CA metal body
at this point I'm unsure of what brand of gears i have

I know, another HK21/HK11 so far i have gone through 15000 rnds on this system without a problem but it's still young

the point of this thread is to obtain advice on increasing my rate of fire without decreasing durability. As many of you know a SAW usually have a very high ROF that tear up internals all the time (5-6 games~20,000 rnds=new piston or more). I don't want a BB hose but a boost in ROF would be nice but what I'm really after an increase in durability. I am using an AEG that wasn't intended to be a SAW. This is the performance I'm looking for:

ROF, I would like to get in the range of 20rps
Lifespan of parts, i would like to replace part as little as possible if at all.

any advice is appreciated and thank you for your time
mateba