There are several good breeders in the Barrie area. Please refer to http://www.labradorowners.com for a listing of breeders that belong to the regional Lab club for this area. Your buyer will know the local towns and such.
Good luck.
I am 1/2 hour from Barrie and do the area lab rescue.
I do know of some of the litters that have pups available.
Also Kim's suggestion of the LOC is a good one as well.