Any S-IPS screen will be ideal for photo processing. At risk if sound like an Apple disciple have you considered the Apple range of Cinema screens. I use the 23" version and once calibrated the colours are fantastic.
To see if your potential screen is an S-IPS check out this resource
http://www.flatpanels.dk/panels.php
Apple to a reasonably priced 20" and moderate 23" and an outrageous 30" but they are worth the money for photo processing.
Not all EISO are S-IPS, be warned!