Â£200 for the PSU alone...? Or for the whole setup?
Anyway, let's try to find you something good and cheap...
If you can find it, http://www.scan.co.uk/products/550w-...-quiet-fan-atx
is an awesome option and it's typically very cheap for what it is. It appears to be out of stock at Scan but if you can get it elsewhere, go for it.
is your cheapest option and it's a good unit for the money. Nothing wrong with it really.
is a step up in quality and can deliver an extra 72W of 12V power, but you won't need the extra wattage with your setup.
is also a good little unit.
is also cheap and partially modular.
And finally I just noticed this one: http://www.scan.co.uk/products/520w-...x-scan-exclusi
-- I was not even aware it existed and Scan claims it's exclusive to their website. I assume it's the same as the original non-modular Antec Neo Eco 520W, which makes it a good unit.
Edit: the Corsair GS500 mentioned above is also a good option. I wasn't aware of its existence, apparently it's a new unit.