I'd say at least go with 9' cataracts. I have an 8' set on mine with the option of putting 1' extenders in mine. That way I can run 8' on smaller rivers or low flows, and 9's when I'm on bigger water.

You can buy them at Sportco. If you keep your eyes peeled, they do put the cataracts on sale every now and then.

Well, I know the blades float. I've never had my oars come all the way off. But I run pin and clips with lanyards. It's almost impossible for my oars to fall totally in the water. You never know, you may want to invest in a set of pin/clips. If you ever want to see my set up, we can hook up. They're pretty cool, made for whitewatering. Basically the same as oarrights but the oars stay stationary and pivot up and down but don't roll. They have their negatives, but I love them.