Rick: I would suggest that you visit a store that sells suits rather than buy mailorder, unless you are absolutely sure of the fit. In addition to being able to make sure that the fit is right, they will be able to answer all your questions and provide advice.
When I went to purchase my first suit, I went to RaceQuip here in Columbus, OH. I tried on a suit that according to my measurments should have fit. What do you know, because I have an ostomy (side effect of cancer several years ago), the suit was not be usable. Well, for every door that shuts, another opens. My wife was looking around the showroom and found a brand new custom suit that had been returned. And it fit! So, I got a suit that I knew I could use, was much better quality than the suit I had intended to buy, and for about the same price.
Just my humble opinion. Your experience may be different.
BTW, I wear a SFI 5 with long underwear! And I am considering CarbonX or something like it.