I had a Kokatat Supernova suit and liked it. Well made and the neoprene neck was more comfortable than a latex gasket. I had no issues with leaking in my Supernova and the fit was roomy enough to allow for layers. I wore a medium weight wool sock with mine in cold weather and my feet stayed warm & dry. I sold it because I just wasn't using it that much & I needed new oars.
I have no experience with the NRS suits. I'd say go with the Kokatat. Great quality suit for a better price. It's a semi-dry suit, but for rafting I think it's a good choice.