I've been to Israel a couple of times on business.
You will want to bring film with you as there is limited selection, spotty availability and it is relatively expensive in Israel. Do not worry about the xray machines used in security. They are the most modern and advanced available. They will not harm your film - OBVIOUSLY, DO NOT pack film in your checked baggage. Pack it in your carry on bag and carry it with you. They will only scan it once but, they will look at pictures from all differnt angles and with different color schemes....rest assured this is all accomplished with post processing. Your film will be fine! Furthermore from what I have seen and experienced, an all manual film camera from the 1970's or 1980's will pass through the various security check points in Tel-Aviv far easier than anything electronic. If you have a personal contact in Israel, firm hotel reservations, or anything official that says how long and where you're staying, your experience will be easier. Make sure you have definite plans! Do not be vague when passing through security at the airport.
You will need to get used to using the 'bulb' setting if you want to photograph inside the churches...a tripod would seem necessary but, the tripod will make passing through the myriad security check points far more difficult (not just the airport...they have security check points at the entrance to many retail stores in Tel Aviv for example. So, I would recommend leaving the tripod home and getting used to setting your camera on something that's already there in the church and making due with that. A few rolls of Ilford Delta 3200 might also be in order.
In the old city, barter is the order of the day. Their tactics are very aggressive...but the US Dollar still has strong negotiating power (they'd rather have dollars or euros than sheckels).
The people are all very wonderful...you can photograph just about anywhere or anything...but do not photograph the "religious people". The do not like it and some get very obusive if they even think that you've photgraphed them...