With recreational kayaks keep in mind that when they're shorter they do indeed turn easier - but the flip side is that the tracking (keeping to a straight line) is more difficult. For flat water & easy rapids I'd probably choose good tracking over good turning.
Perception definitely makes some good boats. Fifteen years ago I started out in a Caspia - about 12 feet long. It was (and still is) a great rec boat. It easily handles class I and class II rapids. The Perception catalog has changed a lot in that time, but this boat has the same general layout and size (plus a drywell).
http://www.perceptionsport.com/kayaks/PRS_Conduit_120
There is also a store in Howland that sells kayaks - Trumbull Outdoor Sports.
Good luck.
Steve Z