The problem is that you're going to two EEA countries and two non-EEA countries. The European Commission roaming price caps apply only to EEA countries, and consequently the best data roaming deals usually apply only to EEA countries. It's fortunate that your first stop is in Italy because
Vodafone Italy could be suitable for you to use in Italy and Greece, and their deal also covers Turkey, despite Turkey not being in the EEA. The cost is €3 per day for 25 outgoing minutes, 25 incoming minutes, 50 SMS and unlimited data. You'll need another SIM in Israel.