In my opinion there would be virtually no difference in wireless connection; they both support 802.11N which is the important thing but the thing that will determine mostly your quality of Wireless signal and internet access will be:
The quality of the router (whether it is 'N' enabled or not)
Your Internet Speed (which you can find at http:/www.speedtest.net) and
The proximity to the router (make sure there aren't too many 2ft thick lead walls in your way
Even though 'N' is capable of 70Mb/s your internet connection will be less than that (unless you live in Japan or South Korea or pay a stupid amount of money for your broadband) and will most likely be less than 10Mb/s as well.
In terms of MMO it really depends if the CPU/GPU/RAM are good enough to render it in real time (I'm pretty certain these PCs can do it with ease though.)
So my conclusion is that it doesn't really matter which you pick for this sort of thing.