Check this thread that I wrote. I talk about how I bottled conditioned my beer and how I calculated how much sugar and yeast to add. I'm on my phone so this seemed the best way to give you the information. I only bottle condition so can't help you with force carbing.
I don't understand what you're trying to accomplish. Are you trying to figure out whether to go with one method or the other? Or are you looking for a best practice outline for one of them?