Graphics card related question from newbie.
If that is the mid-2012 (i7) model, or newer, it should be okay with the Sony cameras' video files. I use a much older iMac for Sony AVCHD without problem, and have just ordered a current MBP with the dual graphics option. I use AVCHD and .mov files from Sonys, including an RX10, GH2/3, and even a couple of GoPros, usually 1080/60.
None of these systems mean that you'll be able to process next year's 4k codecs, but we all know that.
"Knowledge is good." Emil Faber