Need help building 2 machines

Hi there everyone..

I always appreciate the advise of the knowledgeable people here on TH..

I need to build 2 machines and I need input on both..

Machine 1:

The first, I just need a nice desktop that will last 7-8 years like my current box.. my price range is $600 max (ideally)

I dont have any requirements, except i'm leaning towards the famous Antec 900 or Nexstep case.. and I want quad core Intel and ideally Intel mobo.. No other requirements really.. Any advice? PSU ? Cheap HD graphics card? 1TB Sata, Ram, etc?? I'm a windows guy not linux, so I know if I run 64-bit Vista I can only max out at 8GB RAM.. which is fine with me..

Machine 2:

This one is for a friend - I need to build a nice machine that can run Autocad and 3DS Max smoothly - Besides quad core and like 8GB of ram and a HD graphics card - What should I be looking at?

Appreciate any input..

Thanks