The AT is considered the easier and more commercial of the two. Which to choose will depend on your goals, shape, time, and experience. If you want local advice I would see if there is a hiking club nearby or someone really knowledgeable at the outdoors/REI store.
One thing I became on convert on when hiking the CDT a few years in a row is ultralight gear. I had my gear under 30 pounds for a week’s worth of food and 2 liters of water. Even more impressive since I am 6’6” and my gear and clothes just weigh more by virtue of being bigger. Ray Jardine’s book completely changed my philosophy and enjoyment of hiking.
