The HD 5750 should be decent enough. The GTX 460 is the best performer of the three.
See following review and look at the benchmarks for 1280x1024 resolution. That resolution is about 25% higher than yours. Performance does not scale up or down linearly so I would estimate maybe you will get 20% better performance than the benchmarks for 1280x1024.
However, those benchmarks are based on a test rig with an Intel Core i7 920 @ 3.8 GHz which is more powerful than your E7500.http://www.techpowerup.com/reviews/Powercolor/HD_5750_Low_Profile/6.html
The most demanding games in the review are Crysis and Metro 2033.