I bought it at Airsoft Atlanta. They are primarily a mail order outfit, but have a showroom in Atlanta, so I drove up there to have a look-see before buying one. I also bought a propane adapter while I was there.
Here is their online link to the pistol (the description is incorrect, it is not a Caspian Hi-cap):
http://www.airsoftatlanta.com/WE_MEU...ag_p/66545.htm
I got the gas cylinder upgrade from Evike:
http://www.airsoftpost.com/product_i...ducts_id=32277
Another big online store is Pyramyd Air
http://www.pyramydair.com/