go with the G36C-- they use a better gearbox than M4's, the hop-up is easier to adjust, and the mags are stackable and not very wobbly. Not to mention they're more uncommon than the overused M4 :p JG has a large variety of affordable G36 variants that typically fire in the 370-390 range
Nothing you said is true, most g36s run version 3 gearbox (Which can be dropped into M4 Bodies as long as you get a wider pistol grip for the motor housing). you can always buy a m4 magwell adapter so it can run m4 mags.
M4's are not over used, the reason so many people run them is not because there cheap, its usually because it's a very reliable platform that takes standard 5.56 magazines. I bet anywhere you run in a big milsim game there will be tones of guys with stanag mags running guns based on the M4 platform just so they can swap mag with other people on the field. Just because it's affordable and shoots a high fps, doesn't mean it's good.
JG makes a few g36s but I would never recommend them, One shoots 380 out of the box, known for faulty trigger connections causing the gun to be unusable. ARES HK g36cv known for having the gimmicky blowback feature to fail and cause gearbox issues. If your going for a g36 style, run it in a m4 platform , such as the ICS G33.
Honestly its stupid when people say the m4 is a bad platform cause its "overused" my mags don't wiggle, shoots 380 fps,and i can and have used other people's mags when i've ran out at milsim games. The Hop up on an m4 is ridiculously easy, I don't get how you can say a g36 is better. all you do is pull back the charging hammer to have the dust cover drop, revealing the hop up chamber, turn the hup up gear clockwise or counter clockwise until it shoots straight. how hard is that?
I'm not trying to pull an "M4 is the master race!" but its more universal then any other gun, your more likely to run into a guy with more AK mags or M14 DMR mags then before you run into a guy with g36, G3, Sten, Box, p90, mp5 or UMP. Its not because there uncommon, its because there impractical with the magazine styles. Also g36 mags tend to cost a lot more money then a STANAG or Banana mag.