I am wanting to purchase a Retina imac for when I return to uni in January. I will be using it to research, SPSS (stats program), office, surfing the net etc. I might put windows and bootcamp on it so I can play a few games like the Sims 4 as well. I won't be doing any photography/video editing on it. What specs would you recommend? I definitely want to keep it for at least 2-3 years.