I guess I'm going to present the counter argument to Kris, I'd go with the networking, especially from a career perspective.
I know a lot of 'network guys'; on the whole the make a shed-load of cash, and if they're really good the job is easy because the network is solid, stable and doesn't break often (allowing them to impress the boss with a lot of work on command-line techie stuff, like IRC
). I also know lots of really good and dedicated devs who get paid a pittance for their level of ability.
From a hacker/security perspective I'd say you need to know both. If you can't code you're going to struggle to understand, modify or create the tools you need to get the job done. Likewise if you don't understand networking then you're going to struggle to understand and implement some the the attack vectors. But you can get by with a little of everything depending on where and how tightly you want to specialise.
Additionally if you decide to practice the otherside once in work, programming only requires a compiler(or interpreter) and a text editor; it's slightly harder and pricier to get you hands on a corporate level network full of Cisco gear....
Ultimately go where you're passion is, it is going to be hard to keep up to date on any aspect of the IT industry over the next 10, 20, 30+ years of your career if you have little interest in the subject matter. Don't get too tied down with 'where you want to be' and go with 'oooh, cool....'. As a real world example, at your age I was intending to be an accountant (yes I know
), ended up taking computing instead of IT due to a subject clash, sat through the first lecture on binary tree algorithms (sent 99% of the class to sleep) and never looked back.
If you enjoy it and are good at it you'll have a good career and salary opportunities whatever field you go for. (I was expecting to take a salary hit by turning away from accountancy to IT, but now earn more than a friend who stayed on with accountancy. I love my job, he hates his [and he's probably more intelligent than me to...])
Have fun & good luck.