I might consider a poodle-jacket BC, but I use a wing. The idea is you need to be able to doze off and keep your head above water so a wet or drysuit alone won't do the job alone. The added buoyancy is great but not enough. In any case, I would also grab a life jacket in case the BC sprung a leak, to give to another person, or for some of the extra goodies a lot of them have attached.
The best of all worlds would be a survival suit like this:
Mustang SOLAS Immersion Suit
They are standard dress on North Sea Choppers.