Raven,
One of the most important things to ascertain is what service does the helo belong to? I can help you with Navy and Marines, I use testors paints, but you said you can convert-
Navy-The boots should be dark brown or black based on time period. If the model is post-Vietnam (roughly) to 2000 the boots should be black. After 2000 the boots would be a dark brown with black laces. I would recommend a black primer with italian Dark Brown (or just dark brown if you don't have any luck).
For the flight suit, it looks like you are going tan. The Navy uses tan and green. For the tan, I would use flat light tan with a brown wash. For green I prefer medium green with an olive drab drybrush. Nametags and patches are multi-colored depending on the squadron. The tan flight suits are pretty uniform in color, but the green ones can actually vary quite a bit in shade depending on when they were made and how much they've been laundered.
For the flight gear vest, medium green.
Sunglasses will be gold frames with gloss black lenses.
If you are doing the brown leather flight jacket, they are not authorized for flight and are not worn while flying, but use the italian dark brown (with a semi-gloss coat) for the jacket, and italian dark brown over black (with a flat coat) for the cuffs and collar. Otherwise, use olive drab for the green nomex flight jacket.
Marines-boots are black only (as is the nametage).
Flight suits are green or tan as above.
Jacket and flight gear are as above.
If a flak jacket is involved, that's more likely Army (I haven't seen the Navy or Marines use them, not to say they never have). Flak jackets are olive drab and are all pretty old so I would use some lightened drab and weather heavily.
If you are doing an army helo, they have newer flight suits that are 2 pieces and are in the ACU pattern I think. I would google it. Good luck!
Groot