I live in the north Chicago suburbs and would think you could find many qualified designers to help with this project. You have to start somewhere, getting recommendations from friends, then doing interviews to see if you 'click'. Where did you get your plans? You say they are 'architect plans' - from someone you worked with or from a website? If you look on Houzz under modern shingle style, look at the photo credits and see if there are local architects. I know there are plenty in MN as I have an inspiration folder filled with them - for some reason that style is plentiful there. Those architects may be close enough to get you some local recommendations for a designer if you explain your situation. I'll put in a link to a design firm that might be a fit for you - I'm not associated with them in any way, but did use their services many years ago. It will require some homework on your part but I'm sure you can find a good working partner for this. Good luck - it will be interesting to see your project.

Here is a link that might be useful: Fredman Design Group