Jon1270
Minister of Fire
You'll have relatively few choices of NK bars, and very few NK chain options. The rails on a NK bar will be narrower, so they'll wear faster than an otherwise similar standard-kerf bar.
Basic laminated NK bar
Nicer solid, replaceable-tip, standard-kerf bar
(broken link removed to http://www.ebay.com/itm/Stihl-23RS66-16in-Chainsaw-Saw-Chain-B17Q3-/332019306698?hash=item4d4de490ca:g:qdcAAOSwknJXzeu1)
Basic laminated NK bar
Nicer solid, replaceable-tip, standard-kerf bar
(broken link removed to http://www.ebay.com/itm/Stihl-23RS66-16in-Chainsaw-Saw-Chain-B17Q3-/332019306698?hash=item4d4de490ca:g:qdcAAOSwknJXzeu1)