What resolution are you gaming at ?
EVGA is a more reputable brand, but Galaxy is good as well.
I am playing at 1900x1200,
I have one more question, with the different brand will one card performs significantly better than the other? like will the EVGA GTS 450 performs better than the Galaxy GTS450? or there won't be a change in performance?
I wouldn't recommend that card for that resolution. That card was mainly made for 720p resolutions. It does well at those resolutions but at 1920X1200, I think it can run games probably at lowered settings.
If you can expand your budget, I'll at least get a GTX 460.
The Galaxy does have better clock speeds than the EVGA, so it may be slightly faster.