Eyeing the Dell Ultrasharp 24", but...

I am thinking of buying the 24" Dell Ultrasharp monitor, but it has a resolution of 1920x1200, which is a downside for me, because currently I have a GTX580, and a monitor of 1680x1050 resolution, so you know while having l gaming I'll lose some good frames, why is isn't 1920x1080? Is there a same monitor like Ultrasharp but of Full HD resolution only?
Also I need the best picture quality, is going for IPS a good choice?

Thanks.