MP5 upgrade

[DarkAlman]

Ok so I bought this CA MP5 last month, and the stock parts have already failed me. The retaining clip on my hopup unit has snapped off and my gun miss feeds on single which I have been told is a result of my tappet plate and nozzle.

Since I have to replace them anyway I figure I might as well put in a bit of an upgrade.

I know a fair bit about upgrading but I still have no idea what brand of parts to buy/look out for. I've spoken to 3 local gunsmiths and each of them has their own opinion on parts so I'm at a loss.

I've seen my fair share of poorly done upgrades, I just don't want to end up with bad parts or a cracked gearbox, shredded piston teeth etc.

I'm looking for reliability more than anything else.

Desired result:
350 FPS max
close to stock firing rate
needs to drive off of a mini battery (8.4v 1400 mAh)

I believe I can keep the shell, and the CA bushings are metal.
I also want to keep the stock gears.

So I figure I need:
Nozzle
Tappet Plate
Spring
Spring Guide
Piston
Piston Head
Hop up unit
Motor*
*Only reason I want to swap the motor is the stock CA motor is LOUD

So what brand of parts should I be looking for?

[CDN_Stalker]

Stock TM parts will serve you the best, aftermarket ones are sometimes flaky and difficult to deal with when you mix brands and types.

Spring, go for a Prometheus 110 spring, should put you around 330-340fps.

Bearing spring guide (make not important) should up the fps by 10-15fps.

Metal bushings, Guarder or System are good.

Motor, TM EG700 is stock for MP5s, EG1000 also works. I've had both, prefer the EG700.

In my two MP5s, my main one has an SD front end (was originally an A5) and M4 slither stock. I installed a 330mm stock barrel. Has a GOOD PDI 150% (I say good because it's getting rare to find a decent PDI spring that is within spec, most are too long or made of too thick wire, will bust your stock mechbox within 1000rds, if that) bearing spring guide, metal bushings, Guarder clear (50%) hop up rubber, shoots 385fps, not the fastest rpm out there but chugs along well enough on my 8.4V 3300mAh battery.

My other MP5 (PDW style folding stock, Navy front end) has just has a Prometheus 110 spring, metal bushings, Guarder tappet plate and Guarder clear hop up rubber, use my Intellect 8.4V 1400mAh mini and it rips fast. Haven't chronied it yet, but I assume it to be around 330-340fps.