Depends on what you want, Don. If dimensions are unimportant to you and you only want some corrosion protection, then just choose the cheapest ones.
What I would do is start by typing 'washer' into the "Find products" window on the left. Then click on "round hole" in the right pane. Then the screw size you want (eg 1/4") and material stainless steel. Then scroll to the bottom of the page, and look through the selections. P/N 96659A106 (SAE standard washer in 18-8 stainless) at $3.93/50 looks like a good choice (assuming 1/4" is what you want).
IOW, enter the parameters you know (eg, round hole, hole size, stainless steel) and then look through the list of items that match those parameters.