Actually, when you think what he's biulding it for I think you would be best to go for the NEO 4 Plat. It may not be as good as the Asus, but as it's more or less only better or worse on a personal preference level, your friend would probably find the integreated creative 24bit sound the better advantage.
Unless of course the sound doesn't matter, and tweakability is, then the Asus would be better - But as you are biulding the system for him, I highly doubt it.