Flint is...
-Steel Brigade Delta body and helmet (there was no way I was going with neon green here)
-Random ROC Gun, that is as close to something realistic looking but still a similar feel to the 91 gun
-30th Airtight vest
-25th Hawk head (this head looked as close to Flint's as I could find minus the beret)
Amazingly no paint at all.
While I could stand the yellow of Clean Sweep and some tones of blue for Ozone, Neon Green for my Eco Warriors Flint update was never gonna happen.
Flint is a soldier and while he certainly would suit up for Ecological combat, he'd want a uniform slightly less garish and slightly more military looking. So I went with the Olive green of the Steel Brigade Delta, whose mask also makes a decent passable update on Eco Flints mask.
Combined with Airtight's vest I think we have a decent update on Eco FLint.
I chose Hawk's head because in my opinion it was the closest look to Flint sans beret.