I have the Santa Rosa Macbook Pro, and need to get an external monitor. I was looking at the 27" Ultrasharp - someone told me that the Santa Rosa might be too old to work with it. It has DVI - but can the graphics card output smoothly?
The Dell Ultrasharp 27" looks to be a great monitor.
Be aware that it goes on sale now and then, with prices that range from about $630 down to $580 or so. Might be worth waiting for a sale or hunting up a coupon code somewhere.
I got the same computer and run a direct dvi connection to my 1920x1200 24" Samsung monitor no problems. You should be fine the graphics can handle it, your computer isn't that old.