I bought these replacement grates at Amazon.com after figuring out which ones to get at the Weber Grill replacement parts site. They show you pictures of their grills and help you narrow down which ones you need.
The replacement grates that I needed where a different model # than the ones that are in stock at Home Depot. Ordered on Tuesday, delivered on Thursday.
They look great. I won't show you how bad the old grates looked. ;-)