First of all, Id suggest a GTS450 for a dual core, the CPU will hold back the 460 by a bit for some games. What do you mean by "Factory Overclocked" anyways? Is it an OEM machine?
Anyways, there are lots of monitors available in this range and I would suggest going to a local store for the convenience and the sake of shipping charges just in case you get one with a bad pixel or one you don't like, monitors are one of the more personal items when specs aren't everything.
I really like Samsung's offerings. I own a 2494SW and it is really really good, great picture, clear, awesome contrast when games are dark, nice and bright colours without even using enhanced effects. And it was only $210 Canadian.
and a 21.5" 1080p that newegg no longer carries. I've had the 21.5" for about 2 years and the 23" for 6 months. Both are great looking with good black levels for LCDs and work flawlessly. No dead pixels in either. They seem to make good screens, almost all of the have 5 star feedback ratings at the egg.