Battlefoam is pretty tough for day-to-day transport, kicking around the house, etc. Despite the supposed improvements in shipping practices, I don't think I'd trust its crush-resistance for international shipping. Metal (or Pelican) case wins here.
KY Multicase's foam gets mixed reviews from me - it's very soft, which is great for the figures. It's very soft, which makes lifting trays out of the cardboard box a real pain. More than once my trays have folded on me, despite my best efforts, either dumping minis out or slapping them into a pile in the middle of the tray (admittedly, these are old metal ogres, knights, & the like - much heavier than most Malifaux minis).
If you already have a bunch of battlefoam trays, you might look into Vaultz's Letter/Legal aluminum chest - they retail for about $60 at most office supply shops, and are a bit shorter than a BF 720 (although trays have to be "wiggled" past the hanging-file-folder lip, as I recall). They probably also have something suitable for Sabol trays, although I haven't looked.
And, as Webmonkey said, put the aluminum case inside another sturdy shipping carton.