Photoshop For Mac Jmu
Here is what jmu recommends you purchase based on your major and the. (graduated) and I still use it now with premiere pro and photoshop. Amazon's Choice for 'photoshop cs6 for mac' Mastering Photoshop Made Easy Video Training Tutorials Learn v. CS6 & CS5 DVD (Windows/MAC) by TeachUcomp.
I did the DVC concentration, and for that i had (and would recommend) the macbook pro with the RAM upgrade. I could see why having the 15' would be better than the 13' when video editing or using programs like Photoshop, but I went with the 13' and I love it. You can get educational pricing through both JMU and straight from Apple, not sure if there's any difference between the two. If i remember correctly, if you buy it from JMU you get an extra warranty from the school, but don't quote me on that, I graduated a couple years ago and all the beer I drank at JMU left everything a bit fuzzy. Best of luck.
I know lots of SMAD students and from what I know about the work they do, a Mac isn't just recommended, it's essential. I'm not a SMAD student, but as a hobby I do a lot of multimedia work. I bought a Retina MacBook Pro in 2012 and it's held its value quite well; I think today I would buy the exact same computer. A Retina Pro 13-inch will (for the most part) provide all the power you'll need at a reasonable price point.
Mac os x yosemite. My business is viable if I limit my software upgrades to every 3 years – it usually involves an upgrade of hardware which also adds to the cost.

Apple will probably give you a better deal on the computer during their back-to-school sale (although sometimes the bookstore has competitive sales, so be on the lookout for those) but if you buy from the bookstore you get a great warranty that gives you free repairs at the JMU helpdesk. Something to consider. I'd recommend. You'll have to decide wether you want to buy directly from Apple or from the bookstore. It comes with 8GB of RAM, and that's probably all you'll need since it also comes with a Solid-State Drive, which provides a huge speed boost (especially for video editing).
I saw you were considering the advertising concentration? I'm just getting into that one but I know that it's not really necessary to get a high powered mac. Honestly if you needed to you could get by with a PC as there are labs you can use in the SMAD department full of iMacs. I have a hand-me-down Macbook pro mid-2010 with new SSD and it works just fine. If you buy a mac through the JMU bookstore you can get a pretty decent deal but I suggest maybe comparing prices just in case.
If you have questions about SMAD or anything feel free to PM me!