New Computer

Hi all,

So I am looking to get a desktop computer for some gaming and photoshop. I was originally looking at the Dell XPS 8500 with i7 and nvidia 640 gddr5. This seemed good but I don't know how well it will perform for games. I am looking at simcity and sims3 and photoshop mainly, and it will be running on a 27" 1920x1080 monitor. Is there another computer to buy for under $1000 that will do this better, or can I build one for this (I am really inexperienced with this) and will it be easy enough to do? Or will this computer suffice for my needs?

Thanks!