For most purposes the iSight built-in the MacBook is far better in terms of resolution. Granted, you can't adjust where it points independently of the MacBook, but for all other considerations it would be better for you to sell it to someone without an iSight who could use it. Mac Pros, Mac Minis, and pre-2006 Macs could all use it. You can't otherwise use it with that model.
MacBooks don't run iOS. Go to Apple menu -> About This Mac to find out your Mac OS X version and please add that to your signature or any questions that are operating system independent.