The NH-D14 is a better heatsink, no doubt. But, if your ram has tall heatspreaders you will have fan interference problems between the intake fan and ram, especially if you are running 4 sticks. But that can be worked around too. And that is a hell of a good price on a D14 too.
As for adding a second fan to the Macho, the heatsink is drilled for a second set of mounting clips. But the heatsink doesn't come with a second set of clips. Plus, since the design of it is set back away from the ram, you most probably won't have much room on the back side to mount a second fan. If you look in my review and look at the pics of when I ran it in passive mode, I mounted a gutted out fan frame on the back side to act as a funnel to the rear exhaust fan. And you can see how close it comes to the back fan. Plus, it really doesn't need a "pull" fan since it's so close to the case exhaust fan.