If it's a choice of exactly those two flashes, then the SB-800 because it actually works on your camera. That's a good price for an SB-800.
Since you're not really into photography, you might want to check out the SB-400 which is way more compact. The SB-400 supports bounce flash, which is the reason most people get external units.
The SB-800 zooms with the lens and has way more features. But it's a big thing to cart around.
Are you buying a flash because you've decided the built-in flash isn't up to it? You can do a lot with the built-in flash and home-made diffusers and reflectors.