Well, the first thing that struck me about BCAS is they only list crap UTG guns on their site. The site itself looks to have been cobbled together by a 5 year old. I will stick with established dealers here in BC before I even bother to email BCAS.
AIM is not, strictly speaking, an airsoft retailer. AIM stands for Alberta Industrial Models. I have pm'd the owner before, and he is an airsoft enthusiast who also does some film supply. He does not actively engage in retailing, but will order on behalf of someone, as he has the necessary import permits.
Never dealt with Canadaian Airsoft, but it seems they are out of stock on most things. Like others said before me, use the retailer links abovbe.