I have a fibreglass kayak for the St.John and Kennebecasis River and Bay of Fundy. I do like the idea of a sit on top because it allows you to dress for the water without overheating. I don't think a sit-on-top or any kayak should be too wide however. The main drawback for being too wide I think is that it cramps you paddling style. It is not so bad for a canoe where you might sit up higher or use two paddles. My kayak is 23.5" wide and 16.5' long and it is very easy to paddle.

I haven't done too many floats but I would like to try that. There are many good rivers for that here such as St.Croix, Magaguadavic, Hammond, and I think the best way to go might be some kind of plastic, although my fibreglass kayak is beat up enough now I wouldn't mind scraping it up some more as it is repairable. If I was to do a float with it however I would pack as light as I always do which is pretty much just as ultralight as when I hike, except I bring some paddling clothes, and a few extra blue foam pads. I'm like the princess and the pea when I go paddling.

Here are some videos, not mine:

This shows some good technique in various different craft:
http://www.youtube.com/watch?v=LtxkS9G5y-g

This is more my style. <img src="/forums/images/graemlins/smile.gif" alt="" />
http://www.youtube.com/watch?v=Q0eAmIHljcY