Looking GREAT Gunny!
I really like it. Definitely get a KAC QDSS-NT4 suppressor if you want a military Mk.18 Mod.1, if you want one but don't want to replicate any military look then go with whatever suppressor you'd like. It's all about preferences.
Where did you get the Socom Gear barrel nut for G&P Receivers?
Also, is that a G&P 553?
-Luis