It's how I learned how to build computers -- by upgrading and fixing my out-of-the-box HP. The one I built afterwards went together without a hitch.
And I'd shop around for a local computer company to build it to spec, or maybe get one of those custom-ordered ones from mwave.com. Since you're in Hawaii, getting an Alienware serviced could be a huge pain in the ass. Whoever you buy from, make sure you can get it serviced on the island.
All of this assumes you know what you want in the computer. There are plenty of people here who can tell you what parts to buy. Then just put it together yourself, or get it put together at a local shop or by Mwave.