Speaking from experience, the NRS would be happiest with an 80 mm travel frok on it. 100 will work "okay" but the handling will be strange.

I ran 1 Marzocchi X-fly on my '01 nrs air and a Marathon S on my '02 air.

I have a Black Super Air on my hardtail, and the adjustable travel might be just the ticket for your ride and style.