Contrary to popular belief most International players (especially the senior guys) get bats from everywhere.
e.g. I know for a fact that Sachin gets bats from BDM, SS, SG, BAS(heaps), Larsons, Newberry, Bradbury(atleast 2 bats), A few from laver and wood and couple of other small factories in Jalandhar.
Sometimes he just sends his old bat to be copied - other places he walks into the factory to feel some and select a few. e.g. when he is in Delhi for a game he drops by the Meerut factories once in a while.
The logic behind getting bats from many places is to do with increasing your chances of getting the best of the best of the best. Being wood - a natural product one never knows which place did get the "best batch" for the top grade willow.