Hi,
This is on my own reading, and is not legal advice.
The BC Body Armour Control Act requires a permit to own body amour; however the related regulations state that those with a PAL for firearms are exempt.
S 2(2) of the Regs: (d) is an individual who holds a valid licence issued under the Firearms Act (Canada) authorizing the individual to acquire or possess a firearm.
In that same Act it also requires vendors to sell body armour only to those with permits or exempt (e.g. if you have a PAL)
As for import from the US, Level III and higher body armour, OR military designed/in-service body armour is controlled by ITAR; you would require US Dept of State approval for individual importation.
Generally speaking, anything IIIA or lower is not State Dept controlled, and may only need a Dept of Commerce BIS form done up (much easier).
Canadian Border Services CAN take an interest in your import; I ordered a ballistic helmet from the US, and got a phone call from CBSA asking why I bought it. I still received it, but ppl are watching. I'm not sure if a Canadian IIC is required, although some vendors may insist you get one (this is online).
If you're not .mil/LE Bulletproofme dot com based in the US will sell soft armour to you; as for hard plates you can try some Canadian retailers (M&P Tactical, MSA Paraclete, heck even Armor Express directly etc) with an explanation of your situation...if no joy, you'll have to try the Isrealis/EU (I think we have another board member looking into that option...you may PM if you want more info)