I've been working out and my regular shirts are becoming tight. I'm 5'11'' 180lb. I normally wear a Charles Tyrwhitt Extra Slim Fit (15.5''/35''). I'd like to stay with the brand if I can, but my shirts are almost skin tight at this point in the chest, back, and shoulders. If I stay with the Extra Slim Fit and go up to 16'' or 16.5'' in the neck, is the rest of the body larger as well? Or does just the neck change? If I move to a regular Slim Fit, does it change more in the chest, back, and shoulders, or in the waist? I'm looking for a shirt that's very tapered, basically. CT is the only brand I have experience with. If you have experience with others, please share. I live in Chicago, so if there's a local store that works too.