I was lucky to find these guys:
http://olympiatools.com/index.php?osCsi ... 4&cPath=40 on sale at Costco. The ones I got are actually 2 drawer (but they bolt together to stack higher). They were only $30 ea and came with a bunch of SAE hardware. I consolidated the included hardware down and got lots of organizer space to work with.
As for stocking HW, I just try to buy a box of 100 even if I only need 1. If I get anything of a particular thread type I make sure I have suitable washers and nuts as well. It turns out the Discover Card cash back rewards include Ace Hardware gift cards, so I've burned through quite a few of those.