There maybe slight fitment issues although I believe the majority of fitment issues have been eliminated since those bodies first appeared on the market. Originally there was difficultly with magazine fitment,proper nesting of the hopup in the upper receiver, extreme tightness inside the body and even slight "pinching" of the me selector plate. Like I said though, those were earlier models. Besides any issues can usually be fixed with a dremel and some patience.
Unless you have one lined up in Canada you will not be able to order that specific receiver from that website as there are laws that restrict its importation.
"Its only a little bit on fire"