If you let the chips soak for longer than a week, you will get a strong wood flavor, not the nice oak flavor you are looking for. I always recommend cubes, for a number of reasons. Chips are done giving oak flavor after one week, cubes go for 6-8 months.
One ounce is a good starting place. Soaking them is fine, and I like the flavor it gives. I let my beer age on oak for 3-5 months after a good soak in some bourbon, and I find that after a few months in the bottle, the bourbon mellows and the oak becomes more noticable, so don't judge it right away.
Also, don't add the bourbon that you used to soak the oak in when you keg. Toss it and wait until the beer is done aging, then taste - if you need to add more you can.