Dynaudio c2 or c4 - need some help

Thanks for the thoughts. Unfortunately, I am pretty stuck with the room (3 of the 4 walls are existing and not really an ability to move the other much without starting a war with then wife (also, the wall i could move in a bit is the 18' and would only get it closer to 16). Recognizing it is far from ideal, my thoughts were to make the room as solid as I could (double dry wall on walls and ceiling with green glue and acoustical ceiling panels) and then use treatments after learning where the problematic areas are located.

also, recognizing the issues, would it be better to have two small subs (for example, JL fathom 110) versus one larger sub.

yes, will be for ht as well. Will have solid door (sourced from acoustical solutions in Richmond, va). Might do the same as u on the windows -- will see once in and listening.

In terms of ratio, exact size is long walls each at 18'6" and two short walls each 16'9". Ceiling is 7'8".