Wher do you find these bottles ?
Seriously? Do you not bother to look in the champagne section of any store in Chicago?
I’m not trying to be a (complete) dick here, but almost all of what has been mentioned is easily findable in and around the city unless you are willfully living under a rock. Marie Courtin, Laval, Bereche, Roederer Starck (I mean, for real???!!!), etc are all carried by major distributors and have placements across the city that are findable without much trying.
One I’d like to add - Roger Coulon Esprit de Vrigny Brut Nature. I haven’t seen this producer mentioned very often, but of late what I’ve had has been pretty darn good.