I would throw another piece of advice from my own experience (Mentioned in JP's article): use standard oak chips in primary while the yeast is fermenting the wort. Unfortunately there is a variable to consider if you are going to use this method: How long the primary phase will last vs. how long you should have the oak chips on the beer. This will determine how much oak to use.
So, my suggestion would be to skip this primary oak for your first oaking experience. If you plan to make this same stout again, take good notes on how long everything took so that you can make an educated guess about the amounts of oak.
Lastly, make sure to sample often if you are using chips. I've had to remove beer from oak within as little as 2 days before. It will sneak up on you fast if you aren't paying attention. This isn't as much of a concern for cubes or used chips, but always try to be safe.