the reason I was asking is because there is a 21 gallon set-up for sale on ----. The tanks are bigger than 20 gal. and they are also located in Chicago. But if you interested in at least looking at the picture and can't locate it yourself let me know and I can e-mail it to you. I think the asking price is $3500. for the whole setup.
Scratch my last post, I guess I should read before I type. You could always ask an architect or just go to your lfs and check it out. Just try to copy the setup. Shouldn't be too difficult.