Quick Skimmer Question

[SmallFry]

Thanks everyone, I knew I'd get some decent info here. I'm setting up the small tank again for my wife, and unlike last time I set it up I want to make sure I get a decent skimmer. I might be able to get a second hand SWC which was why I mentioned that one in particular, but if that doesn't work out I'll definitely look into some of the others..