drysuits... ...are damn near impossible to paddle in & weigh a ton. go have a browse through the wetsuit review thread that's stickyed to the top of the main forum page. lots of useful info in there.
yes you can surf with them and yes they are good. they're very stiff, but keep you warm. it all depends on preference. if you're looking for maneuverability over warmth, then go with something else. if you get cold easily and dont really care about flex, then get a dry-lock. but i would only suggest using one on the coldest of days, def not a december suit