Hi Frank,

There is no problem dual booting with Vista and any other OS. I don't do any programming, but I am running Vista 64-bit and I love it. It has been stable as a rock, runs smoothly and is very fast. It has great memory management as well.

If you go with XP (32-bit) then you cannot use all 4GB of your RAM. Only 3. If you want to use more than 3, then you will need to go with a 64-bit system.

The Asus P5Q is the motherboard I am running. It is a great MB! Good choice and it is not expensive, either (compared to some MBs).

Since you are getting Sata drives, you might want to look at getting two 500 GB drives instead of one 750. It might actually be LESS expensive and you end up with another 250 GB. With raid, they will act like one big drive .

I know that this is something that some people disagree with, but I would get I bigger power supply. It will do you good if you upgrade some parts later that require more. 450 is kind of borderline these days.

I am sorry that I don't know a lot about your video card selection. I am running an Nvidia GeForce 9800 GX2 (1GB) and it rocks!