From what I have read you can buy a full upper from Brownells but anything that has itar on it you require an import license I believe (or a export but a specific licence none the less) this will cost you $250 for the year so if you plan to buy a lot of itar parts it may be worth it. What I have read is a much better option is when purchasing you call Brownells and tell them the story and they will have no issue sending the item to an importer inside the US with the item paid for using a Canadian card. This importer (IRG does it, and a few other site sponsors) will charge an import fee ($20-$80 I think somewhere in there) and they will bring it in and ship it to you. Better then paying the $250 license fee but it would have to be a darn good deal on the upper as after shipping, tax and exchange rate plus the import fee you could get on for almost as cheap in country. That’s my understanding anyway. But you still are capped at a $500 limit I do believe.