I'd suggest going to a store that has several brands/makes of wetsuits. A swimming wetsuit has to fit you comfortably, esp. under the arms. I ended up getting one at Triathlete Zombies in Santa Monica when I was down there. They had a room full of wetsuits, and the brand I chose, Blue Seventy Reaction, came in many sizes that fit all parts of me. The store has a good Web site, too:

 

I splurged, but feel it was worth it. I have never been cold; I also ended up getting a Hot Head swim cap, and booties, which I don't wear all the time.

 

Good luck!

Lyra