Your graphics card should be able to do directx 10. Everything is moving toward DX 10 with Vista. Are you going to run the hard drives in a mirror? You DEFINITELY should, even if it means doing to mirrors with 4 hard drives. Most PC motherboards (ASUS) come with 5.1 The memory is awesome, you could get the ocz low latency, with multiple screens and many apps open you will see a difference with more ram.

Save all of your software, before you install any third party programs, update all your windows updates and then all of your drivers. Save all of your drivers on your mass storage, that way if your main drive crashes, you will have everything backed up. Seriously do at least ONE mirror. Don't live on the edge.

Make sure your power supply is more than adequate as many accesories/peripherals are now taking advantage of using the power of the pc.

PM me with any questions, please provide links because I am LAZY!