Your choice entirely depends on your specific need. The water body you may use it on is important, if you go for a smooth brook you have one choice, if you go for a narrow winding stream then you have another choice while if you go for an ocean you have some other option and the list keeps growing. You should also think of the goal of buying the canoe, family outings, downriver racing, slalom racing, day trips, overnight camping trips, or fishing.
There are various aspects you need to think about before buying a kayak. Some important aspects you must consider are mentioned below :
1. comfortable seat.
Look for good back and hip support, and take the canoe out for a try before buying. If the seat is not comfortable, you will regret later on.
2. Cockpit or sit on top.
Sit on top canoes are superb for beginners who fear to be encircled in a cockpit, and for fishing. And they won't swamp if it rolls. While, cockpit canoes are great for those that loves wild currents flowing against them.
3. Fishing kayaks.
Fishing
kayaks should be 12 - 16 ft long and wide enough to be stable and as discussed earlier, is better to have sit on top sitting arrangement.
4. Weight issue
The canoe for a 150 lb male will not be the right size for somebody 220lb. Weight is a vital issue for kayaks as it is about stability.
5. Slalom kayak.
Also called whitewater canoes, these are shorter, with a tighter turning radius for navigating more "active" waters
6. Touring kayak.
Also called sea kayaks and these are best for travel on open seas and lakes.
7. Experience matters.
Stick with the long established canoe manufacturers for the best tradeoffs of stability and performance.
8. Hire a kayak.
If you can lease different models, you will have a much better feel for what works best for you. This is preferably one good idea before buying a canoe.
River kayaks are very personal and I will advocate you try many types in numerous conditions. For me, a season pass to a kayaking centre is the most cost effective approach because I do not have to store or transport the ship , I am able to employ a new state of the art kayak each year and test many different designs.