The military clothing site, Out In Style has a wide range of kid clothing, including a camo diaper cover, long- and short-sleeve camo baby t-shirts, and a camo dress (available in woodland/blue pattern only).
You'll have to find the indian and construction worker clothes on your own.
Even as you Google for Onesies, I would caution you against any attempt to turn a trademarked brand name into a generic term. Onesie(R) is a highly regarded--and carefully guarded--trademark of Gerber Childrenswear, Inc. Google, on the other hand, is apparently a random word picked out of the aether. Who knows how it came to be synonymous with searching the internet?