...But it doesnt have Facetime HD camera...
And you have a problem with buying a separate camera?
http://eshop.macsales.com/shop/video/web_cams
A separate camera would have the advantage of you being able to keep using it when you change monitors.
...because dvi supports up to 1900x1200...
To use monitors larger than 24" (higher resolution than 1080p) you need a dual-link DVI adapter. I don't know exactly what cable you'll need for the Dell. (I tried to get a Dell sales rep to help with attaching a U3011 to a client's Mac a few months ago. No help at all.) The client and I gave up and Apple got the sale.
IMHO, I'd recommend the Apple Cinema Display simply because you avoid all hassles with finding the correct cables and adapters. If you were only going for a 1080p monitor (which would use a normal mini-Displayport/DVI cable) then it would be simple to find an appropriate cable or adapter. But the dual-link gets complicated unless you get a knowlegeable expert or a sales rep that's willing to work with you.
(edit: to clarify, I'm recommending the Apple Cinema Display because you're looking at monitors larger than 24". Otherwise "small" monitors, I don't have a problem with other brands because they don't require dual-link cables, which are an issue since you MBP use a mini-Displayport and you'll have a more difficult time finding the appropriate combination of cable and adapter(s).)