Its really not a good idea to leave your new bird so early in the relationship, but if it cannot be avoided then you have no choice. They need this time to bond with you and set up the trust you want to build with them. Also so early on like this, the bird may possibly bond with whomever is taking care of it while you are away.
I doubt it will cause stress for the bird, especially if the person or persons taking care of it will be around some for it to get used to them before you leave. I guess it is not possible for the breeder or whoever you are getting it from to keep it until you return, that is what I would suggest.
Maybe some of the other members have some other ideas, but for the first year it is best for you to be around every day for the bond and trust to be properly set, but then again it may not matter at all.
I notice this is your first post, why don't you introduce yourself in the welcome room and tell us a little more about you and this new grey you are getting.