series 2 = 2012 onward, main difference is touch screen standard (colour) and different front headlights / front bar.
Series 1 = 2009-2011 can get colour non touch screen, or green screen which looks shit.
Other than that it's all in the options, leather, reverse camera etc. I wouldn't worry about series 1 or 2 more about what options they have & a tidy one.