Just curious what you find to be lacking in the kit lens? (Except for the build quality of course) I've always heard good things about the image quality from that little thing.
Personally, if you know that 17mm is going to be wide enough for you then I would give a serious look at the 17-55mm EF-S lens. I was highly impressed with the quality from it when I had my 7D still, and I would gladly buy it again if I had a crop body and still used zoom lenses. You could also consider the Tamron 17-50mm f/2.8 as well, I hear it's a very good option in addition to the Canon.
Regardless, it sounds like the 20mm f/2.8 isn't the lens for you right now, sorry mate!