I need a computer professional's help on putting together my own computer?

Tweet

I've been trying to find out what's best for the kind of computer I need to put together (I want to buy the parts and get it assembled). I have/play lots of computer games (30 to be exact), but only 19 are installed. What specific add-on should I get for more room/space (hard-drive space right)? It takes a long time for the game to load when I click on it. What specific add-on should I buy to make it work faster and load faster (I want it amazingly fast. ram and processor right?). And when I'm playing multi-player or even just me it lags and freezes (you know how frustrating that can be. What can I do/buy to stop this?). I play a lot of games (Counter-Strike, Half-Life, The Ship) that require a graphics card. Which graphics card will give me amazing graphics that I will be amazed by? I also want to hear every single thing clear as light. What sound card will give me surround superior hearing? This is my dream computer, someone please give me advice and help on what add-ons to buy.