Sepulcrum's right. It'll cost you twice as much in parts to build one, and you still can't get the receiver in Canada, which is the restricted part. And you don't have a clue what you're doing, so you'll more than likely have to pay someone to assemble it eventually, that's providing you can find all the parts.
You're better off getting one in Canada. And that's about $350 minimum for a JG. And the only way to get them is to be 18 and age verified.