I bottle out of the keg now but didn't have too good of luck with the few flip tops I had when bottling. They are notorious for leaking CO2 and you'll need to replace the gaskets frequently. I would stick to capable bottles for a much better price.
As far as 12oz, 16oz, 22oz,... Use all 3. I bottle a few 22s and 16s so I have the option of drinking a little more with a serving.