West Marine, despite some of their high prices their SS hardware is fairly reasonable. Acklands orr Steveston Hardware, but I doubt that you live in Richmond. Any fasterner supplier will have SS hardware, hopefully at reasonable prices. Check your phone book.
I picked up a 500 piece stainless screw set at Harbor Freight for $20. Unfortunately they don't seem to carry it any more, just one with tiny screws that might be good for trim work.
I bought some stainless steel square drive deck screws at Home Depot, those work well for some things.
For bolts I've been buying 1s-2s at fleet farm and the like. Not cheap.
