NEW EDIT SETUP FOR HD AND CS4 - HELP NEEDED

I am currently looking for a new editing set-up, and any help would be grealty appriciated.

First of all, can I point out that I am pretty much I.T. dyslexic. I’ve been editing on a PC based system for the past four years using Premiere Pro 1.5. We bought it from a 'edit suite' suppliers for over £2000, whilst it has been very good, I'm not sure I need to pay that much again for the same results. The system also had a Matrox card, which was handy for using an output monitor, but not a lot else, and wouldn’t be looking to upgrade that.

I am looking for a PC based system, and will be using Premiere and After Effects CS4. At the minute we are shooting on the Panasonic HD P2 system, and though we may change format in the future, this system will be used for HD footage.

Briefly I would like a two monitor set up and a third calibrated monitor and a system that can be as powerful as possible for the money. My budget is about £700 (approx $1150).

What I really want to know is, what’s the best graphics card to go for, how much RAM, processors etc.

I’ve read that if you use windows Vista64 that you can go crazy with the RAM? Is this the best option?

Also, I’ve read your post about RAID. We work with external USB hard drives (normally 500GB WD), one for each project. Can you set these up as a RAID system? Is there any advantage, other than the potential of losing the footage (if so, we back everything up anyway)

If anyone can supply me with a list of parts that would be terrific. We are in the UK, don't know if that makes much difference to model numbers etc.

Many thanks in advance.

Again, thanks in advance.

Ben