We have got the similar questions recently. Please check out the following threads for some insights first...
If your means of communication is mission critical - even during your vacation, then money is no object for the convenience. It is likely an one-time event, not worthy for subscribing specific plans which designed for heavier usage pattern for extended period outside the country. Perhaps you should consider the two-way satellite communication too. Otherwise, it is not worthy for the expensive charges.
So enjoy your trip in the sunshine
HC - NO "i"
I am NOT "the" HC, we are TWO different individuals!
"If we amplify everything, we hear nothing!" - Jon Stewart, Comedian