Nice report and pictures. Looks like it was a good time.
Some kayaks are more stable then others right out of the box but the main thing is that whatever you're on you will feel and be more stable over a little time as you get used to it and get experience on it. My Malibu Stealth 14 has to be one of the most stable kayaks that I've ever been on but I'm sacrificing speed for stability. My advice is to ride as many as you can to find the right feel, stability, and speed that you will be comfortable with.
Demo days are a good start.
Good luck.
