Alternatively a high end 24 inch monitor would be the way to go. You may want to consider a 120hz refresh rate as it's meant to provide a very smooth gaming experience with sufficient frame rate.
One option could be this:
http://www.overclockers.co.uk/showpr...d=17&catid=510
It would also give you the option for 3D in the future should you choose to pick an nVidia vision kit.
Slightly more expensive is:
http://www.overclockers.co.uk/showpr...d=17&catid=510
This also sports a 1ms response time which is as low as you're going to find.
Really it depends what you want most from your monitor though - IPS panels can provide better colour reproduction (Better for films, photo editing etc) with slightly slower response times and lower refresh rates. However I get the impression you're asking about the best for gaming so I'd say 120hz would be for you.
The Acer I linked only recently arrived at ocUK and has picked up a lot of positive reviews so it looks like a pretty good bet.
Also 120hz is this BenQ - could also be worth considering
http://www.overclockers.co.uk/showpr...odid=MO-070-BQ