If you want to stick to AEG, why don't you replicate a real steel piece?
if you want to use gate in it, build a big DMR.
One idea i am toying with is creating a lower that I can put on different uppers. Each upper would have different parts for different performances
AW Hi-Capa 5.1 X 2
EMG DD MK18 Cerakote
VFC M4 MK18
TM MP5 First gen
TM MP5A5 with swordfish 2004