Hey guys, thank you for your replies, however, I just can't afford the displayport monitors, over £150 more expensive. I can get an active switching miniDisplay port - DVI dual adapter for around £30, and I can't spend £120 extra.
What sort of problems occur? Is there a make / model where the problems seem least prevalent? All the listings say that Macs aren't compatible - is this true, even with the adapter?
Are there any fixes for the problems? If it's a matter of running my computer on discrete graphics 24/7 - (that's the fix for the flickering issues), then, i'm happy to just live with that.
Please tell me if the model i suggested before would work (technically). Sorry if it seems like I'm ignoring your advice, I would love to be able to take it. In an ideal world, I'd own a Cinema Display, but I spent all my money on my laptop, and this is all that's left.