Get both the international plan (if you are planning to use data) and a local SIM for voice/text. You can prorate the cost of international plan only for the days that you were abroad, and using a local SIM is a lot less expensive than using the International plan to make voice calls. You can either use the SIM in your Tour and switch between CDMA and GSM radios when you need to switch from data to voice use, or (simpler) just bring along another unlocked GSM phone to use with that SIM.
Unfortunately, you cannot get a prepaid SIM in Israel that combines both voice and BIS data (in EU, you can i.e. Vodafone has both prepaid voice and BIS data).