Ryan, if you are considering having a shirt made-to-measure, unless you have someone local to do it for you, may I suggest here:
http://www.shirtsyourway.org/

Proceeds from there benefit the museum!

And Robert, good thought on the bias tartan waistcoats. You know, I had never considered that, but perhaps the fashion of waistcoats with tartan on the bias came about from a desire for a more form-fitting waistcoat. After all, the reason the tartan cadadh were traditionally on the bias was to allow for a more snug fit across the lower leg. Good thought!