New Computer Help In Process

As of now I am currently trying to make the a really nice computer to its fullest potential.

Specs:
MB: Asus Rampage II Extreme
CPU: i7-920 2.66 GHz
Harddrive: 320 GB Raptor possibly 2?
PSU: 1000Watt Thermaltake
RAM: Corsair 8GB DDR3 2000
Monitor: Hanns-G 28"
GPU: 4870 x2 and another one so two in total.
Sound Card: NEED HELP CHOOSING 2 OF THEM ONE FOR HEADPHONES AND ONE FOR SPEAKERS! I really want the BEST QUALITY to hear a difference!! Help choose speakers as well. Headphones I will use Dr. Dres headphones.
Chassis: MID TOWER Armor+. Hopefully it will fit everything because it does quiete seem very big for a mid tower. If not please tell me.

1. Will 1000watt PSU be enough for this?
2. Any components I should change?
3. Since it will produce a lot of heat what do I need to do to keep it cool.
4. Is it possible to make this computer cheaper, but with the same amazing performance (Keep in mind I am trying to make a computer to its fullest potential)?


Thank You for those who helped me and took time in reading this long list of stuff.

You can change the following things in your build:

1.Raptors are overpriced.Get Samsung Spinpoint F3 500GB for much cheaper.
Very nice drives and fast too. Another option:WD Caviar Blue/Black 500GB.

2.Get Corsair 850HX instead of TT 1000w.

3.Ditch that GPU for sure.
Get single 5850/5870 for now.Add another down the road and enjoy better performance for much lower power consumption.
DX11 is a plus too!