Definitely spend a lot of time planning this out. 3 grand is a shitload of money and will get you an amazing computer. You're going to want solid state drives, SLI, watercooling, etc.
15 Gigabytes of RAM is a bit much unless you'll be doing stuff like playing 4 full res games at the same time.
I'd say go with 8 Gigabytes if you're not going to be using it all because then you've got extra money for the other parts.
Are you aiming for a gaming computer?
Also, you want to get a motherboard, and a power supply that will suit your card, and board.
I suggest getting the parts from newegg.com
Good luck!
Pretty good computer bro, I have a quad core with dual GTX 560 TI cards.
Well with $1,800 I built a top-end machine... With $3000 you better be getting a nice motherboard and then get two graphics cards for it. I highly suggest water cooling your machine and then over-clocking it for even better performance.
Wow, $3000 for a computer thats an insane build! my computer has 4gb ram hd screen and 450gb memory was only £200.
wow tight budget, your PC will be crap........ jk
If you got that much money, then get the best you can with the $3000.