I couldn't think of a better title that explains what I'm after

Long story short, I'm starting another brand aimed towards more streetwear and fashion oriented products, so I'm interested in some sources for things like waxed cotton canvas, oilcloth and classic metal hardware. It doesn't have to be milspec, but I'd go for the level above the nickle plated crackpipe.
Anything else to consider or things that one needs to know before buying?