Help me making a 1,000 US$ gaming machine

Hi guys, recently I killed my Dell XPS M1530 by letting some water drops which came from the can of compressed air onto the motherboard. Now, I won't buy another laptop, because I have a netbook, and I only do some word processing when I'm not home.

Now, I'm trying to build a custom gaming and video encoding PC using a budget of 1k US $.

I have never custom built a PC before, so I need some help:

What I want the computer to have:
- 4 GB of RAM DDR3
- A decent video cards (I don't know the prices for desktops)
- Intel Core i7 with 4 - 6 cores.
- Nice 7.2 KRPM 320 GB or more hard drive.
- Motherboard (I just don't know which one to choose...)

What I already have:
- I have a DVD ROM drive from my older desktop, so I won't need a new one.
- Samsung Monitor. 1080p. So no new one will be needed.

And I can't think of anything else... I really need something that gets me out from the netbook. I can't use Firefox, Opera, and Flash/Dreamweaver altogether at the same time.

Thanks in advance for all the help.

I doubt that it's practical to build a Core I7 system for $1000. If you want 6 cores, that's ridiculous: the I7-970 (the cheaper of the two Intel 6 core desktop CPUs) is about $880 (www.newegg.com) by itself.

This article is a little dated (July 2010), but it gives you some idea about budgets:

Build the Best Gaming PC for Any Budget - How To by ExtremeTech

Note that the AMD six core CPUs are much less expensive than the Intel 6 cores, but their performance may be comparable to similarly-priced Intel CPUs.

The Core I5-750 (or 760), with a Socket 1156 motherboard, is a popular choiuce for gamers. The Socket 1156 I7s have hyperthreading, though, so they may be better for video encoding. (It's not something I do, so I can't speak from personal experience.)

Thank a lot Guys, saved me the day , Ill try to compare and see.