Hey vito, Mah shlomcha? Meyefo ata?
You might run into a few different problems. When you are buying bulk it is not likely to be in a container with the hechsher on it as in retail products.
Also, what products are you looking for specifically? You might have to strike a deal with the manufacturer to buy in bulk. For protein supplements I have used a manufacturer maxi-health. I eat pig myself but once I was staying in crown heights NYC, and needed kosher protein.