Both of those are going to produce the same results, like lowering your 60 ft time and stopping wheel hop! Whiteline and Eibach make some of the best suspension components available for Mustangs today!
You've linked to two of the best control arms on the market, but I went with the Whiteline Adjustable lower control arms on my 2011 GT and the on-car adjustability is awesome (not that the Eibach kit won't be). I just planned on doing Whiteline's Watts Link kit and wanted to keep all my suspension components the same and the non-binding bushing design was also appealing.
But honestly, you can't go wrong with either brand. We've used Eibach on some of our project cars and had great results! Either way, once you decide on a kit let us know how you like them.
Let me know if you have any questions or need some assistance!