OK, I've checked out the situation. I thought I'd got it working in Windows 7 - actually, I think I hacked it to work in Vista. As you say, you can use the Nvidia Control Panel to support a high resolution desktop but you're limited to 1600x1200 in games.
There's probably a way to fix it, but it doesn't matter because a DVI-A cable will definitely work. I strongly recommend the LDD-1020BL - available from Amazon and some other place. The thumbscrews are very fiddly but the signal quality is good.
Don't be tempted by 'high quality' DVI-I leads from the likes of Startech, they don't work.
I've just whacked my two C220p monitors back up to 2048x1536, and with text increased from 100% to 125% it's quite usable. Here's hoping increasing text size doesn't break any applications - last time I tried it made incoming remote desktop a nightmare.
Unsurprisingly, I also got my monitors off ups-trader and would definitely recommend them for UPSes as well. I agree that at the price there's nothing to compete with them, although I do like the brightness of my TFTs