I don't know about your rivers but I've had Clack drifters for the past 10 years+.
My first one was a 14 foot drifter and the latest one is a 15 footer with the new chunnel hull (2002 model). Depending on your budget, I would recommend a 15 foot boat, they are so much easier to handle Vs. a 14 footer, extremely light and will handle all sorts of water conditions. Also, if you can, get a model with lots of dry storage space, like a storage bin rower seat and dry bin pedestal seats. They are really nice to store cameras & other such baggage. Lastly, make sure you get one extra break-down oar, the last thing you need is to be up the proverbial creek! I've never broken an oar but have seen it happen...
Pete AKA Frenchcreek from Calgary