I am also 6'4", as Mr Fox above, and my neck is 18.5". I wear my suits with braces, high-waisted and pleated, though. I have them made wider at the knotting point. I get my grenadines as 4-folds and my prints as 3- or 6-folds. I order them 59" long. To me, the knot and the trou height are the deciding factors.