I'm about your size and it sounds like we have a similar build.
For me, the key wasn't size so much as stretch. I spent a miserable 2 hours trying on rental suits for my OW. All of them were older neoprene styles, very stiff, so nothing fit right, and it was torture trying to get them on. The only one that came near fitting was was a 3XL, what was way long in the arms and the legs...diving with it was not fun.
When it came time to buy, I got a Henderson Hyperstretch in only single XL. It is just a tad long in the arms, but it is flexible enough so a tug here and there, and it is not a problem. I'm thinking that at 6' (I'm 6' 1"), a lot of the 2XL+ suits are going to be real long on you.