just thought I'd add my 2 cents to this EXCELLENT thread.
I've gotten hardware at a place in Baltimore called Maryland Metrics.
www.mdmetric.com
They are a great shop that has ALL kind of hardware. They would be a great place to check on some of the more obscure hardware that can't be found elseware.
I was pretty happy with their pricing, but I have no idea how they compare to some of the other places listed so far.
Also
Wurth is a really good professional place to get hardware and they have JIS Automotive as well.
and lastly.....
you all need to get one of these cool gadgets!!!!
lets you quickly figure out bolt size and thread pitch. I think it was like $10???