I guess if I had to choose between those two then the second one would be better I think. The reason I'm not sure is because the only GTX 555 I know of is the 555m and it's a mobile cpu. Plus it comes with a 330w External power supply ? External ?
The second build is a good Pc but wouls be even better with a better video card , all the other parts are good and would make a good Pc build and here's the thing; the first build is $1149 and if you take the parts of the second build and add a better video card you would then be up to the price of the first build.http://www.tomshardware.com/reviews/overclock-radeon-hd-7970-core-i5,3210.html