Can I upgrade my GPU?

[peasantnoodles]

I want to upgrade the GPU on my atc-605-ub11, but I'm not sure what size will fit in my case. I know that I'll probably have to upgrade my PSU, but I don't want to get a PSU with a GPU that doesn't fit in my computer. Can anybody tell me, by looking at these pictures, how big my GPU upgrade can/should be?
Use this newegg link for the pictures and specifications:
http://www.newegg.com/Product/Product.aspx?Item=N82E16883103924
I appreciate any answers!

 

[peasantnoodles]

And for those of you who want to know, I'd upgrade my PSU to a Seasonic 620w if the graphics card demanded it

 

[Archaic59]

If it was me, I'd take the side cover off and measure from the back of the case to the hard drive cage. If it looks like the video card would clear the hard drive cage, measure up to where it would hit something, like the front of the case.