Well if we take a look into the near future we can see some pretty nice peaces of hardware coming out.
First off I would strongly suggest getting Nvidia and Intel.
For your Video card I would recommend waiting till Q1 of next year, for the 9 series cards to come out for Nvidia, there going to be the same price as the 8 series cards but two times faster.
For your processor it's kinda preference issue, either Dual or Quad. So far Dual is destroying the market and Quad is still poking it's head out of the hole. Although we are told that most games will be optimized for Quad Core technologies in the near future. So you can make the decision yourself, either way both processors will be very good.
As for the RAM I would suggest DDR2 although DD3 will be used very soon. But anyway, you should have at least 2 Gigs of RAM. And remember to get the DDR2-800 or the DDR2-1000
A good site to look at is
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more! or
TigerDirect.com Best Deals - Computer Parts, PC Components, Computers & Electronics for prices and or buying the hardware.
The Mobo is completely up to you, and since you have had a history of making computers you should know how to get a compatible Mobo
Hope that info help out some and hope you get a uber cool PC