You're going to need to get open water swims in anyway, so I'd see if any store near you rents wetsuits. That way you can try them in a swim to see if one brand / model fits you better than another when swimming. I've got a 2-piece Desoto as well, which is very comfortable and relatively warmer than the QR I used to have.
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2007 QR Lucero
2005 Cervelo Soloist