Calling all techies

So I am buying a new laptop this summer, and I need some advice from anyone who cares to give some. I have just been comparison shopping Dell, Gateway, and HP, and it seems that HP has the best deal. I've already been told to go for speed in the laptop itself and relegate things like DVD-R/RW and bigtime memory to external devices. This seems like a very reasonable thought. Ideally I would like to get the fastest cheapest most portable laptop possible. I will primarily be using it for video and music editing/watching/listening, internet, Office, that kind of thing, just general use stuff, but I want it to be as fast as lightning and last for a long time. I'm looking to spend around $1,400 including external drives, excluding scanner and printer, which I will buy once I get a job. I am looking for any useful thoughts, especially basic things that I haven't considered. What do you say, am I walking into a minefield? Am I missing a crucial piece of information? I did notice that HP strongly recommends that you get 2gigs of DDR memory with Vista Home Premium for $100, even though I know you can get a USB flash drive that will do the same thing for much cheaper, so clearly there are monkeyshines to be avoided.