well, the gutter guard stuff is aluminum and yes you can go to home depot to get them. Cost me about $3 to get a ~15' x 8" roll as i recall. I don't know if they have other types of more durable grills or if they are aluminum either.

Check out cryogen97's(i think that the name) site for some tips on how to preserve the gutter guard if thats the way you decide to go. He has a tip I believe on keeping it from oxidizing after being outdoors so long. I didn't do it to mine, but this is the second one I've done and I can tell a slight difference on the surface. Its not rust, just not as shiny.