Will these fit a 2002 Chevrolet Z71 Suburban?
Sorry, but it is not fit for your car. It fit for 2004-2006 Chevy Suburban.
Will this fit the 2018 Nissan frontier?
No, the fog lights do not fit the 2018 Nissan frontier.
Is this for two lights - as in a pair, etc.?
Yes. 1 pair of fog lights, with 880 12V 27w bulbs.