I will join in the fray.

Like everyone here who has contributed, it is strictly our own opinions. Your key words here are..'u can afford...' If so, go for 16gb as there is never too much of a good thing and you never know when you will need the extra byte. Who knows? After 'playing' with your iPhone for a while, you want more apps, movies, songs and what nots and that is the time you may regret not deciding on a 16gb. iPhone is a powerful tool and you just might need the extra juice once you get what it can do.

Susceptibility to scratches is not reliant on colour. But it is more obvious if it is black. Of course, the phone being dirty depends on how one takes care of the unit and what protection he/she has on it.