Go find a place that rents first, and try them out.
I was thinking about a short light kayak, turned out the best for my needs is 4 feet longer than what I started with, and 400$ more.
If I'd rented the Pelican (8'9") before buying it I wouldn't have bothered. It turned into a great "Play toy", but It's a real effort to paddle, you can forget about traveling in a straight line in any sort of breeze or current.
Determine whether you want a recreational or expedition/touring type.
I use a 14' Dagger with a rudder now. Bought it used. My emphasis is on fishing, and that involves covering a lot of territory in windy, rough conditions. (Try launching a kayak in heavy surf sometime. It's a real kick) It's a great rig, weighs somewhere around 50 pounds unloaded, probably close to 85 with all the necessities.
I've paddled 40 miles in the thing and didn't fatigue at all. (Okay, with wind and current, but it was sitill 40 miles!) I wouldn't have gotten 10 miles in the Pelican.
Anti is right. Kayaking is risky. It's a lot more physically demanding than most folks realize. You need a good boat that matches the water you're in, good safety gear, and a good plan.
One last thing. Kayaks are like guns. They cost about the same, and you'll never be satisfied with owning just one.