The naza has plenty of 5volt outlets!
The f1 and f2 connections from the top down are Negative/ground (at top), 5volt + middle pin, and the bottom pin is a PWM output usually refered to as the "Signal" line. The two spare connectors next to f1/f2 can also be use to draw 5v from.
I recently added most of my phnatom pics to a Flickr account (I don't know **** about Flickr lol) but if you search "driffill" or "ADriffill" you should find the few set I've uploaded, in the rebuild set I have a bunch of pics of where I've ran wiring etc, including pulling 5v from the naza . . .
I dont have written detail with the pics yet tho pictures.