have you tried out any DSLR yet? go with anything that you feel comfortable with. consider the feel, user interface (menus, layout of buttons, etc...), expandability (availability of lens? accessories? which you can purchase in the future), ease of usage.
i agree with cheersjy. since it's just a hobby... and you're just about to step into another level in photography, get a camera that's affordable, at the same time consider which of the cons of the dslr that you can still live with and shoot (maybe noise level?).
imo d80 is fine for a start.