I spent under $1000 and I ended up replacing the motherboard, CPU, memory, power supply, and fans. I already have a selection of video cards kicking around so it was a pretty cheap upgrade. My new Blackbird operates silently. I kept the same liquid cooler and used a new Intel i7 mount for it. The Gigabyte motherboard fits like a glove in the chassis with very little cable management changes.
If you are going to do this I recommend you pick up a large can of air and blow out the entire system when you pull it apart.
Here is a list of parts I ordered:
Corsair AX850 Power Supply
Gigabyte GA-X58A-UDR3 (why Gigabyte? ..because it's fanless, it's fast, and it's not overpriced. The Asus republic of gamer motherboard seems way overpriced for what you get, don't waste your money)
Intel Core i7 Processor 930 2.80GHz w/ 8MB Cache
Corsair 6GB XMS3-1333 Triple Channel
2 120mm silent 1200CFM RADIAL fans (to replace the top radiator fans on the Blackbird)
New mounting bracket for the liquid cooler (buy a cheap Corsair H50 & dump the cooler, use the i7 mounting bracket)
I received new cards from ATI and Nvidia - I'm still playing between them. Based on the individual performance of these cards it's unlikely that I will install two. One video card is more than enough to deliver the performance I need in all my games at 2560x1600. By using one card my machine is also quieter and it runs cooler - and I still run dual displays. It's generally easier to work on as well.I'm amazed at how well my PC is running now! It's way faster, it's much quieter, and it's rock solid!
It's been over three years, and we basically left the premium market wide open after HP Voodoo proved it could design a world class performance PC. There was a time when Henry Ford brought out the Ford GT just to embarrass Ferrari in the 24 hours of Lemans. They succeeded by completely destroying everyone and winning all three podium positions... for four years in a row.
The GT's come back. Maybe the time's right for other things to reappear. What do you think?