C.O.
I would wait until he graduates OCS and gets his follow-on assignment.
I can tell you from living overseas that while getting "stuff from home" is great - sodas DO NOT mail well. When my mom shipped stuff to me - like food she had canned - it was put inside a ziploc bag and wrapped in bubble wrap. Even overseas they will get soda at the commissary.
When I send care packages to our troops - I always put in cookies and brownies. I also include a piece of WHITE bread (not wheat or oatmeal, etc.) WHITE bread to help keep them soft.
What is your brothers MOS? if you knew that - then it would help in picking out a gift for him.
As for the family? Family pictures are great to have when you are overseas. If they don't have skype and a webcam - then that would be GREAT!!! that was all up-and-coming technology when I was overseas.
I wouldn't give the family a gift when he graduates unless you are going to be there and then take them out for a nice dinner!!
Please thank your brother for his service and sacrifices!!!