I'd go with the Ripjaws. I don't think it's worth the extra bit for the Eco sticks because it won't impact performance.
One thing to note is that you shouldn't get the P55A-UD4P. The Gigabyte USB 3/SATA III boards have an issue where if you Crossfire, the higher USB 3/SATA III speeds are disabled. For only $5 more, you can get the Asus P7P55D-E Pro that doesn't do that.
Thanks for the information.
Right now, I'm not thinking about crossfiring, but maybe I'll stick with the Asus just in case for the future. However, I read that the gigabyte chipset or layout? (I'm starting to get into computers) is more efficient than ASUS somehwere. What's your opinion?
I don't believe that's the case. Both are very high quality manufacturers, and the differences between them is very small. The only reason for this functional difference is that Gigabyte boards were the first USB 3/SATA III ones available, and released early to correct a small flaw in the previous version.