To answer your wifes question yes they can tip over but I have only rolled in breaking surf under situations that would have likely rolled a kick boat or even an open bass boat. I have never rolled out side of the breakers even at times when I had a steady wind chop breaking over my bow I just cut right through it. the fishing models offer good stability and I would tend to believe a kayak is faster offering more range and better mobility than a kick boat. However I really can't say for sure having never tried a kick boat. I can confirm that it doesn't take much effort to troll from a kayak. It may take a trip or two to get use the boat and if you go with a kayak you should try some different models before making your decision. Most retailers will let you try before you buy even in the case of used kayaks. In my opionon your best option if possible would be to try both (kick boat/ kayak)before making your decision. I might like the kick boat better, but you might like the kayak better and vise versa. You really won't know until you try.

JerryG