If it's just gonna be a couple of kayaks and ducks I would suggest just carrying your gear or dragging the kayaks behind you. The hike isn't too bad and from what I've heard the pack mule rental ain't cheap.
Just went down last weekend...rolled up and put a Mini-me in a Bill's bag and had another person carry a dry bag down, a cooler, and the two kayakers shouldered/dragged their boats down...
Have fun...it's an incredible section of the Gunnison river. Make sure to stop at Smith Fork Creek for some waterfall exploring.