Just a thought. Being much of the trip we will be away from the hotels and going from site to site, you may want to have a backpack of some kind. Something to have your snack bars, water bottle, a bible and other daily necessities in including your passport(you'll want to keep that on you). There are several out there, and it is easier than carrying a bag around with you. Being close to your body, it makes it easier when hiking up or down certain terrain.
Which brings me to an important part...Shoes! Wear the most sturdy and comfortable shoes you can. Remember you are going to do quite a bit of walking so we don't want those dogs getting tired...we want you all to keep up with the tour guide. Make sure you have a good pair with you, 'cause when yo' feet are barkin', ain't nothin' gonna make you happy!
Your Bible, if you have one, is a great thing to bring. Hey, we are in the Bible's Epicenter. There will be times you may want to read it at the hotel gazing over the Sea of Galilee, or overlooking the ancient city of David or the Heart of Jerusalem. It is a huge privilege to be able to go to one of the most historical countries of the world and read some of the history right from the pages of holy writ.