You can order them from Brownell's yourself too...
I just went through the whole process, just need to get a few documents such as an international import certificate (IIC) from DFAIT, then send Brownell's a document with the parts you want to order and a end user declaration then they will get the export certificate for you. Talk to Sandy Moranville, she's been a champ throughout.
The process took about a month and I saved a good amount of money doing it myself. Also gives you a good idea how to import firearm related items.
I ordered the chassis and a few other items and there were no issues getting the appropriate certificates.