I don't know about the military jackets, but the industrial stuff stands up very well.
If you buy the coveralls they are much tougher than cotton ones.
You can also buy regular jackets, parkas and pants in Nomex and just wear regular clothes underneath them.

If you buy fleece it is quite warm and provides even better flame protection than the normal Nomex cloth.

I find my Nomex fleece hoody just a little too warm most of the time.