Your opinions on this £1,000 computer configuration

The most basic things you'll need are (assuming you have peripherals: screen, mouse etc):
cpu
z77 motherboard
ram
hard drive
psu
os
You can get away without a case if you're willing to risk it being a little exposed.

What do you plan to use this for?

Thanks for the reply. I'd be using it mainly for full graphical gaming with steady fps since I've got to a stage on my laptop where I'm not able to play some games on lowest settings without lagging. So I'm wanting to make a massive upgrade and hopefully this PC will last me a good few years before upgrading it a bit.

intended usage? gaming? video editing/rendering? photoshop?

never heard of Best Value PSU's. unless you wanna risk frying everything off, you're better off playing it safe with a quality 80+ certified Corsair, Antec or Seasonic. and you definitely don't need 900W unless you plan to get another 660ti or two and run it in SLI, OC everything like mad, and make several future add-ons like a water cooling loop. 600W will do just fine, 650W tops.

if you only plan to play games at most, any of the i5 will do, and you don't need 16GB of RAM as 4-8GB will be fine. beyond that, like 3D rendering, an i7 and maybe more RAM will have it's use.

OCZ vertexes and any SSD with a SandForce controller are kinda frowned upon here due to it's poor reliability, with the Samsung 830 or non SandForce Intel SSDs being a better alternative

Thanks. I think I'll switch to the i5-3570K and take a look at 600W PSU's and alternative SSD's.

 

All from aria.co.uk:

MICROSOFT Windows Home Premium 7 SP1 64-bit EN 1pk - OEM [GFC-02050]
Zalman Z11 Plus Black Midi Tower Window Gaming Case
Corsair Vengeance Low Profile 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit (CML8GX3M2A1600C9)
GIGABYTE GA-Z77-D3H Intel Z77 Socket 1155 DDR3 PCI-Express Motherboard
Intel Core i5-3570K 3.40GHz (Ivybridge) Socket LGA1155 Processor (77W) - Retail
550W OCZ ZS Series 80PLUS Bronze Power Supply
OCZ Vertex 4 128GB 2.5" SATA-III Solid State Hard Drive
MSI Power Edition GeForce GTX 670 OC 2048MB GDDR5 PCI-Express Graphics Card
1TB Samsung HD103SJ SpinPoint F3 SATA-II 3.5" Hard Drive
Arctic Cooling Freezer i30 Quiet CPU Cooler

Total price (incl P&P and VAT): £987.80

Gave you home premium as ultimate is expensive
same case as it's a good cheap case I usually put into my builds
low profile ram so you don't have interference with cpu cooler.
good cheap motherboard, you won't be able to SLI but your PSU isn't big enough for 2 GTX 670's anyway.
3570k is an obvious choice if you want a more future proof build as you can overclock it later.
solid PSU which will happily power the GTX 670 and 3570k
Contrary to what Hazle said OCZ's latest "4" series SSD's ,based on marvells indilinx controller, are very good and much more reliable than the "3" series.
GTX 670 will keep you gaming at max settings at 1080p for sometime i'm sure.
Added in an HDD for storage.
And a CPU cooler so things are a bit quieter.