I personally feel the most "canon" layout of teh Cantina is the lifesize blue-print that exists for the large set shots they did... The best scene is the panoramic shot at the heroes entrance into the Cantina itself. It shows the basic size/shape/layout of everything (mostly).
If you're going with windows, I'd just base them on the SS 1:6 environment windows... That's just my take, but the outside of the Cantina has the least material to figure out, so it's a tough call to make I guess. I can't recall if the panoramic shot of the Cantina shows a window or not... Probably not really, since the booths seem hard to see in that show other than where they're placed.