Wes,
I have a USNV-14, which comes with an excellent light headmount as well as quick-attach rail mount that the optic can click onto. To take the unit off your head and put it on your rifle would probably take 20 seconds, without rushing. I have mounted it behind my Aimpoint and Eotech just "playing around" to see how it looks, and it looks fine. So, yes, if you are "proned out" and are planning to shoot at a known target area, I think this would be fine.
But I think I would still be inclined to leave it headmounted, and just use the rifle (with its attached NV compatible optic) normally to take the actual shot. I say this because having to use the '14 presupposes that it's dark, and therefore, you're gong to be doing basic looking around much more than actually laying there drawing a bead on a target.
But I do keep the rail mount in the '14's accessory bag anyway, just in case.
I will also mention that in "playing around," it appears that any conventional "hunting" scope can be used in front of a '14. The magnification is great, and you can see the crosshairs fine.
But with a centerfire rifle, care must be taken not to let the scope recoil back into the '14 and damage it. USNV notes that the '14 is "5.56 recoil proof," so I would not mount it on anything larger. Also, if using a conventional scope like this in combination with a '14, the '14's focus has to be adjusted when looking through the scope versus normal distance scanning.
But walking around in cornfields & trails at night using a headmounted '14 with an IR laser-equipped M4 (preferably a suppressed one, preferably select-fire, which I use) is the stuff of which dreams are made. It's such a quantum leap from the conventional limitations which have been associated with using firearms (needing light, having to shoulder the rifle, having to use sights, needing hearing protection, being visually detected by animals) that it's truly a liberating and mind-bending experience.
Of note, the ONLY way I would have dropped the kind of dough for this setup that is required is by selling a SMG I bought years ago which had appreciated astronomically. The question I had to ask myself was, "Would I trade all this neat stuff for this crude old 1950's Commie SMG?" It was a no-brainer. I also was able to buy a Serbu BFG-50 .50 cal rifle with scope, and a bunch of ammo for it.
I wish I had bought more SMG's a few years ago!
Ted