Some good solid advice guys. Being a white water paddler and my wife says I have too many kayaks sitting around you can find used ones quite easily.
As mentioned above Kayaks go by weight class and performance. Then there are different types of kayaks like cottage, recreational, white water, tripping, extended tripping..........the list goes on. Usually the type of Kayak you purchase from Canadian Tire, Cosco Walmart will be a recreational/cottage kayak. Meant for playing out infront of the cottage. Of course any device can be adapted you your use. The flat botton on these boats make them more stable. The inital stability is good but there isn't any secondary stability. Of course a good PFd is needed in any craft.
The Sit On Tops (SOT) are really taking off and are now being marketed as fishing crafts. There are some real good ones on the market. Great for summer but good paddling gear is required for the more cooler mths.
Go to some of the manufactures and read up on their Kayaks and SOTs. The cheaper ones are good for getting into the sport buy you'll find they are harder to paddle due to the shape (flat bottom) and most people get fed up with them.
Try some of the buy and sells like www.supershopper.com there is always kayaks of different price ranges in there. I bought a SOT for $50 because it had been leaning against a cottage wall for a year or more.
There are also a few good Kayak Fishing web sites now and a few in Ont.
You can buy cheap twice or good once.
RR