I'm trying to put together a powerful computer that will last a very long time. I'd like an Intel quad-core processor, at least 4GB of DDR3 RAM, multiple USB slots, FireWire, wireless capabilities, a fast DVD drive/burner, a good sound card, and a fast HDD (preferably 500GB or over). I need a good graphics card (or two graphics cards, depending on the other hardware) that can handle Counter-Strike: Source, Half-Life 2, and other more demanding games. Also, a case to hold everything together, enough power, cooling, etc. I'll be using the computer for gaming, video editing, graphics design, and generally very demanding operations, all at the same time. It would also be nice if the computer is easy to upgrade as new technologies come out. I have about $2000 available to me (not including the OS, monitor, keyboard, and mouse, which I'll take care of later). I've been doing some research, but it's more complicated than I thought. I'd be grateful if anyone could recommend a build or any sort of advice.