Some stock makers have what they call "try stocks", which is simply a fully adjustable stock in all respects, comb height, length of pull, cast, etc.
When adjusted perfectly to fit you the dimensions are recorded and then a stock is created to those specs for your gun or the original altered if possible.
Who does it in your area will take a bit of research. There is a sticky thread at the top of this page where the fella's recommend gunsmiths, would be a good place to start. If your a member of real active gun club ask around there as there is always someone like yourself altering a stock.
Precision Arms in King City about 20 miles of Toronto is one place I have had work done when I was shooting alot. Steve Milton is the owner/gunsmith. He is British, and apprenticed over there under one of the well known firms. I know he does stock work.
Length of pull is a easy fix, cast can be increased or decreased by altering the stock where it attach's to the receiver, etc.
Depending on your severity of your fit issues a good stock man should be able to diagnose your issues and make the corrections. I know Milton knows his stuff and can do the work. I shot with him many times and I learned alot from him.
But there maybe better fella's out there closer to your location, as I have been out of the loop for several years.