Chips do not need a lot of time. I left them in my secondary for 17 days for my RIS and that was enough, or more than enough, but the flavors are a lot better after a month in bottles. I only used 1oz light toasted oak chips. I would say soak the oak in bourbon. I soaked some vanilla beans and not the oak chips, so I'm not sure if the flavor would be any different. I only used about 6-8 oz. of bourbon, and I don't taste any of that right now. I would say you can double that. If you want to secondary it longer, use cubes and those can soak in the secondary for a few months.