For Ghost its all dependant on what game level you are wanting to do his costume from. On Favela, Ghost wears a Ripstop top with no hook that is ACU style (not camo print, but velcro collar and arm pockets) Tactical Denim pants.
Ive also tried my hand at painting a couple balaclava's rignt now, the first was a fleece and the 2nd a polypropelene hood. The problem with them are they just arent accurate like ghosts. But there isnt actually a balaclava out there that is 100% resemblant of Ghosts.
Here you can see the differences in Ghost's mask to conventional masks.
The green lines show the knit pattern, while the red outlines the eye hole with a solid fabric. So its practially a mix of the 2 (fleece/poly and knit). The other thing is its quite formed to Ghost's face. Curving to the nose easily and as well as his chin.
Now Ghost has multiple outfits, just like all the characters do (Soap, Roach, Rangers, etc). My friend and I are doin Soap and Ghost from Favela, but here is a shot of his full favela outfit.
Then on the household:
And Ghost in his dive outfit:
You can see it switches from a hooded fleece top and Multiflage pants and pouches to the faded BDU/ACU top and Tactical Denim. The reason I feel its tactical denim on Favela are these photos here:
The seam says it all practicall as well as the color. The best I came up with is the Dickies Workhorse...with some work in fading and distressing, should make a good replica.
I've indentified most the real world items used on their persons and being an InfantryMan I'm very familiar with all their gear, so if you have any questions throw them out there and ill supply the answers to what I can.