Help me choose an inflatable kayak?

I'm looking to buy an inflatable kayak for river floats in the summer, but maybe it's use will expand. Anyways, I'm mainly looking at the Sea Eagle 330. My main concern is that it has those fin things on the bottom, of which the name escapes me. I'm worried about those because I'm going to be floating the Stillaguamish, and in the summer, there are a few spots that look like this, so I'm worried the fins might scrape along the bottom and catch and stop the kayak or rip or break the kayak. I'm wondering if that's a valid concern? The 330 is also bigger than I'd like, but I can't find anything in the size I want. I'd like a 1 person kayak like the Intex K1, but I want something that can fit a cooler in it too. So far, I don't think an inflatable kayak of such a size exists, so I'll probably have to get a two person kayak. Does anybody have an input or advice?