Where's the best place & price for quality snap swivels for my 30's and 50's?

[GringoJohn]

I want to buy a bunch of snap swivels in bulk to save a little bit of money this year, but don't want to buy something that would break on me mid fish. I'm fishing 100 pound sailfish and 100-500 pound Marlin on 30's and 50's. We leave the drag a bit light on the Marlin and use the boat alot, so I don't need something so big that I could winch over a big Marlin, just something that's good against corrosion. Don't need anything super fancy, just something that works and won't break! We change them monthly, or when they look like there is corrosion. Websites help the most!