This is really not an answer to your question, but I agree with Food. I went on two kayak trips on the Colorado River below Hoover Dam the past two summers with some friends, and the first year I brought my lightweight gear, including tent. I found out there is a lot of room in a kayak for gear, compared to backpacking, so the second year I brought an old, heavy, but still serviceable 3-person Eureka free-standing tent. Most of the guys I kayak with use large (and fairly inexpensive) dome or rectangular tents. It makes it a lot easier to pitch the tent and since the material is thicker than that of ultralight gear I don't worry as much about sand or debris abrading the floor of the tent.

Cliff