Hey there, folks!

Question for you all- I'm planning on ordering a PC with my wonderful economic stimulus check. I just rented one from the Celtic Croft for a wedding. I had myself professionally measured, and I ordered by those measurements. The vest is too small by about two inches, while the jacket fits like a glove. It says on the tag that it's my size, but it's nowhere close. Is there a difference between Scottish inches and American? I assume there is. (Just kidding here- I know the thinking world uses metric). So how should I go about ordering when I finally have the money? I don't want to spend $400 on something I can't wear.

Thanks!!