I’ve done a fair amount of kayakng, although I unfortunately don’t have my own kayak.
I’ll second what Lost said, make sure you can easily carry it on your car. (You’d be surprised how much a car can carry in terms of boat weight on top, but roofracks (either factory-installed, or bough from Thule or the like) are essential.
I unfortunately can’t give you any brandnames for boats, but the staff at places like Eastern Mountain Sports (EMS), REI, and L. L. Bean are usually quite helpful. If you don’t have any of those in your area … I’m not sure what to suggest.
Canoes are indeed heavier and less maneuverable, but they’re also stabler and have more easily-accessible storage space. All the kayaks I’ve seen, the storage space is situated in the ends of the boat – behind the rear/stern paddler, and in front of the front/bow paddler. (And in water-tight compartemnts.) You can install cupholders in your compartment, and maybe hold some things on your lap, but the latter would be uncomfortable and impractical.
Incidentally, having done lots of canoeing, a good amount of solo kayaking, and some duo kayaking, I’ll note that I prefer canoes or single-person kayaks. In two-person kayaks, you have to be very careful to synchronise your strokes (some would argue this is true for canoeing, as well, but I’d argue that two canoeists can’t do each other physical pain when not in synch.). This works out alright if you have a decent working relationship with the person, but I find it calls form a lot more concentration until you get used to it. YMMV.
A decent one-person kayak should run you anywhere from $600 - $1600, new. Much depends on the material it’s made out. A decent canoe should be anywhere from $900 - $5000. Again, a lot depends on material – and length.
A 9-foot, plastic kayak can be as light as 30 pounds. A 14-foot duo kayak can way over 100 pounds. A 16-foot canoe will be about 75 pounds (lighter if made of fiberglass, heavier if made of aluminum), an 18-foot plastic canoe is about 100 pounds, and I’ve never dealt with the 24-foot variety…
Good luck! There are lots of web sites out there with more info; I’m sorry I can’t offer anything specific right now.