Good! Sounds like a decent hdd! That's obviously a 7200rpm drive right?! Unlikely not to be. Anyway, see how you go if you are serious about obtaining more ram. After installation I'm sure thins will pick uup for you. By the way, there's no eneed to get apple to install it for you unless you're worried about warranty & anything going wrong in the process. See:
http://www.info.apple.com/usen/cip/index.html & you can dwnld a QuickTime movie file to show how to change ram. But also read up about ESD Precautions!!!