Drysuit too constricting? Are you talking about a neoprene diving dry suit? Forget that! Get a good Goretex dry suit and you will never go back to anything else.
I just sold my two full wetsuits and although I still own a couple of shorty wetsuits - one of them came out of storage once last year while my dry suits were being repaired / maintained. The dry suit is so flexible because it fits just like a loose thin jacket and typically has rubber neck and wrist seals - some have a rubber ankle seal or full latex or gortex bootes. During the last two Tybee500s I wore mine every day...even starting as far south as Islamorada. I started by only wearing a thin silk wicking layer and a pair of shorts under the dry suit. Then I upgraded to a rash guard over the silk layer. Then a fleece upper over the silk. Finally for the last leg to Tybee, I put on a pair of fleece uppers and lowers over the silk layer under the dry suit.
I just don't see why you would wear a wetsuit ... oh...except for the mother nature part. It's a little difficult to pee without undoing something in a drysuit. If you are going to get a dry suit - make sure you don't skimp. There's a pretty large difference between bottom and top shelf when it comes to dry suits.
You know there are two kind of people in this world don't you?.....Those that admit that they pee in their wetsuits and those that lie about it.