Welcome to LQ euforia. I will defer to more knowledgable people but I believe that at this point, dual layer burning is not yet supported under Linux. My understanding is that k3b is working on it, but as far as I know that capability has not yet been released. Again I'll emphasize that this is just as I understand things; I would encourage anyone the inside scoop to post back.
As for the player itself, NEC is a pretty good brand and I would expect that it would work perfectly well. If the critical consideration for you is the dual burning function, it may be better to wait for confirmation that the DVD burner apps really do fully support it. Good luck with it either way -- J.W.