a farmer john wetsuit. Usually made of 3mm neopreme. Only thing, most have no feet and are shortsleeved. But can be found in long sleeved. We actually used them quite a bit when I whitewatered. Even in colder water/weather. THey actually have booties of neopreme that fit over your feet. But what you could do is use a pair of breathables over the farmer johns. That way you're warm, you'll float, and water proof. Then add whatever you normally wear over it.
Do a websearch for Northwest River Supply or Cascade Outfitters. They have some great prices on gear I mentioned. I used to get a professional discount, so that was a bonus.
"Good angling ethic is not a monopoly practiced just by fly fisherman" - Bill McMillan