The trackers are designed for extreme sports so they should stand up to the conditions.
I don't think it should be that expensive actually, you would only be lending/hiring the trackers for a short time and not buying them.
The devices are very small and fit 12 in a small suitcase which you could easily take on a plane or ship by DHL.
Maybe they would even do it for free? I would guess the amount of international exposure would be very good for a small company.