I have two questions really.

Next year, I want to landscape my yard along the road, and I'd like to plant a lot of Rosa rugosa, which is salt-tolerant. I've never seen any, though, at my local nurseries. Everyone seems to carry knockout roses. They look a lot like Rosa rugosa, but are they the same thing?

Also, I went to the beach a few times this summer, and the seashore was covered with Rosa rugosa for miles around. I'm going to try planting them. However, I'd really prefer full-size bushes (which is why I'm curious about the knockout roses.) Does anyone know how quickly rosa rugosa grows?