If you're willing to spend money, Crowfoot at BBay has a lot of military stuff.  I think it's mostly for M1/2, though.

For free, there's this Japanese site:

http://www.katch.ne.jp/~naoki-s/download/download.htm

I think the military stuff is for the Poser 4 people, but you could use Wardrobe Wizard to adjust it for other figures.