I think there are other XPS8500 models that would serve better for gaming - Core i5 processor, better graphics than the GT640 (a GTX card minimum IMO).
What price range are you looking at?
Have you considered building it yourself? We can help there.
Actually yes, I am considering choosing all the parts myself but I think I will only focus on the graphics card for now. BTW my budget for the graphics card alone is $180.
Also to my understanding $180 is more than enough to buy a GTX card but is there any AMD graphics cards you could recommend to me that are the same performance and also about $180.
Cpu's, I can help. Why I say the i5 is preferable for gaming is probably what you are wondering. Here's why - first let me clarify that the i5 is not a better processor but the advantage the i7 brings is through a process called hyper-threading (I will not go into what that does but in a nutshell it allows for more data processing). Gaming (currently) does not take advantage of hyper-threading so, in essence you are paying extra for a technology that won't be used. That's it, one simple difference and a price difference. It just comes down to value, an i7 can be used but... why?