i will recommend you buy all your stuff at fry's electronics or go online at
www.frys.com and the place has everything of electronics first you want to buy your case the cases i like is usually is the XION Gaming system cases. Then for your cpu i just recommend you to get the newest intel. by the way you want to buy a motherboard with 4 ram slots and buy 4 8gb ram sticks and that will make you have 32gb of ram on your computer. and for a hard drive Western Digital are the longest lasting hard drives they will not break for 15 years or longer. and for your graphics card if you want a really good graphics card but cheep i recommend Gigabyte GeForce GT 620 DDR3. And for an audio card i would just choose intel but if your really care about audio cards for the greatest sound just buy the cheapest but greatest. and for a cooling fan i would just get a cool looking fan with lights on it. And for cd drive i would get a Toshiba blu-ray rw drive that would be black i recommend for the color to match with a gaming system because they are usally black. But this is a option when you build your computer but when you buy a floppy disk drive i would recommend getting a Toshiba floppy disk drive. last your want to get for you computer is a mouse and a keyboard and for those i recommend Microsoft or Logitech. and for a monitor it is just your choice i would just get a big LCD screen.