The Nitrolon is very tough; you won't damage it.
I like the G2Z over the G2 because of the better switch and it's easier to hold between my fingers.
There is a
LED available for the G2Z (and others) available at BugOutGear.
I carry in my car a G2Z with the LED, and a
Spares Carrier with a P61.
The mod is talked about
here on CPF.
Batteries from Surefire,
Battery Station , or
Amondo Tech are a very good deal. They will cost you $5-7 apiece OTC.