How long do you still have to go before your deployment is over? When are you going to buy these items? Reason I asked is for weathersealing. I would recommend the 17-55 but if your going to be buying it now and using it there, you would probably be better off with 24-70 or 24-105. Add a 70-200 to any of those 2 and your good to go. I believe on the 70-200, only the IS variants have weathersealing.
here is the link for the code for aafes if you wanna check it out before you buy.