Smaller sized boxes get to people faster, so I would probably (depending also on the type of armor you get) send it in it's respective peices. And it all goes through New York or some other big port city customs, and that's the last time that the USPS touches it, so as mentioned, sending it Priority doesn't do a lot of good. Insure it and pray. We can recieve insured packages with no problem, and that way if someone does steal it, you're not out for all your money. And be patient, it can take up a month for a package to make it's little journey over here, hehe.
I would HIGHLY reccomend something with a crotch protector- trust me, the worst thing I've seen over here is people who bit it right below where the flack vest stopped.
Good luck.