I'm 6'4" and usually weigh anywhere from 205-210 and an XL is a perfect fit for me in the field jacket. You should measure a jacket you already own in the chest and shoulders and see how that compares. Epaulet's measurements on the website are on point.
I like e-spoke! I've been able to get jackets made at other places, but the only pants I've ever gotten that I really like the fit of are my Luxire pants, so if I want a suit I'm going to need to give Luxire a try. Fingers crossed they can nail the unstructured shoulder.