Hey man, do a search on pins. theres a post a while back and everyone posted websites and such on where they get theirs and how much they cost, etc etc....
No need to risk valuable body space on syringes, when you're gonna be using that space to smuggle gear. Why run the risk of the syringes being too bulky that they see them, or if the paper makes noise as you walk, and they stop you. Then not only do you lose your syringes, but your very valuable gear, not to mention possiblities of it being on your customs record, fines, jail time, and possible imprisionment.
It's so easy to get them on the web, and they come delivered in 2 days. Cost the same price as mexico, and are terumo which are a better needle than B-D's which they have in Mex.