Well, gigabyte has a less expensive GTX 560 ti card. you can always go for the plain 560 card. Asus has great monitors for under 200 that can handle 1920x1080.
The size of the monitor doesnt mat.... well i should say that. The resolution is the important aspect. The bigger the monitor the, the more your eyes have to look at.
A 23in LCD monitor @ 1920x1080 is graphically equal to a 27in LCD monitor @ 1920x1080. The only difference is how much more your eye's will work with a larger screen.