international insurance coverage isn't really that great. Insure it for its amount, but don't go over as was previously stated.
Best bet. Is package it for the apocalypse. you will probably need one of the large customs forms, since the package will most likely be over 4lbs. The large forms have a degree of traceability if anything goes wrong. So even if your package is smaller than 4lbs for some reason, request the large customs form and not the little 1/3 page sized one. Use the big half/page one.