I am about to purchase Pro 4 and will be upgrading to a workstation.
I was hoping to get some help on components as well as advice on the whole 64 bit deal and which version of OS.
Thanks in advance for any help you may provide.

Based upon my experience with CS3, what I've read about CS4 user experiences, I'd go Vista 64 Home Premium. According to info I've read at Videoguys.com you don't want more than that because it drags along a bunch of stuff you don't need that will slow your system down. I don't have a link, but there's a lot of good system info in their DIY system section. You might want to poke around there.