I realize this isn't a C8, but this photo does show some variations that can added to builds, such as the black stock.
Modified C7A2 while on deployment.
The soldier has added his own KAC M5 RAS( thank you Kokanee for the info!)
My particular project will be roughly based off this.
It also negates the need to find that darn Tri-ad rail. (for now anyway

)

So far.....