Looking for advice: Rig for CG rendering - 1200 pound budget.

Hey everyone, first post here after the forum was recommended by a friend.

I'm currently working at a design agency specialising in 3D work. I spend most of my time working on arch-vis projects which often contain large poly counts that are very memory intensive in both the view port and at final render time.

I'm also heading off to university this year so I really want to get my rig sorted before I start my course, due to some generous scholarships I have a nice 1200 that I can spend on my new rig. I've looked at a few parts so far but but its been a while since I upgraded my computer fully so I'm a little rusty on what's good so if my heading down the wrong path tell me!

I'm guessing most parts will be coming off e-buyer and Amazon but if you know of any other great places that ship to the UK that would be awesome.

Key points:
Ability to calculate and render images fast.
Ability to handle a large amount of view port polygons (fields of grass in maya or a high resolution zbrush sculpt)

Secondary points:
Fast load times for OS and programs.
Computer keeps reasonably cool.
Potential for future upgrades.
Over-clocking potential.



CPU
http://www.amazon.com/Intel-i7-3930K-Hexa-Core-Processo...
This ones seems pretty decent, maybe even a little overkill.

Motherboard
No idea on what motherboard would be suitable.

Memory
No idea on brand, possibly sticks of 4-8gb so I can expand when needed I'm guessing ill need at least 16?
http://www.amazon.co.uk/Corsair-CMZ16GX3M4A1600C9B-1600... Maybe something like this?

Storage
Not needed, already have a large hard drive. I dont have and SSD so that might be worth a look.


Video Card
Currently using a 1Gb 9800GT - not sure if I should upgrade or not.


Power Supply
Current power-supply is 750w guessing I need to upgrade this.

Looking forward to all your advice everyone, thanks in advance.