I just bottled my Midwest Supplies Bourbon Barrel Old ale.
Based on reading the posts here on use of oak and Bourbon I used 11 ounces of Makers Mark, and let the oak cubes it in it for 45 days. When it was ready I added the Bourbon to the beer. I used 45 days so I could gauge the oak flavor, tasting a tea spoon once a week after a month. Some have said the full 16 ounces is too strong, so I used 10 (1 oz consumed in the tasting).
I used the 2 oz of oak cubes, but didn't add them directly to the beer. I had read that you can get too strong an oak taste. Maybe my way will be too weak of an oak taste, I will find out.
There are multiple threads on the use of oak, and on Bourbon.
There is a lot of great information you will miss out on if you rely soley on responses to your question.