Barry,
If you can afford it, and I agree that's a big if at around £800, then the Eizo FlexScan SX2461W looks good:
http://www.eizo.com/products/lcd/sxsp/index.asp
The slide in this 'presentation' describing the gamma processing is a good one to show why budget LCDs such as the one you were originally enquiring about are not particularly suitable for photo editing.