These are the shirts for sale in November 2015. See https://www.runningahead.com/events/fsrcmerchandise for more details, and to make your order.
Regarding sizing, from the vendor:
These shirts fit pretty true to size. Below are the specs for the long sleeve shirts. The short sleeve shirts would fit the same but the sleeve length would be different.
BAW (Performance Shirt and Jacket)
Port and Company (Cotton Shirt)