Help on first game

I posted this on the G+ community but thought I would repost it here too.

Tonight I will be running my first game of the playtest doc (kickstarter version) and something struck me. I plan to run the Kirosawa extraction for a one shot that could lead to an ongoing game.
I am considering the twist being an opposing group of runners.

When the characters "mix it up" trying to eliminate a enemy using their fabulous gear, they do harm to the NPC, how do I apply that to the NPCs? There are no "monster stats" for opposing forces. Do I just pick a random number and when that is reached then they have been dispatched? I know the combat isnt just a kill everything but how do i gauge how they ar doing vs their enemies? Are their any guidelines?

I have played in a lot of AW style games but have only run dungeon world so maybe that has tainted my thinking :-)
Some guidance would be appreciated

Think of enemies as sinilar to your PCs, with the same stats for weapons and armor. Usually give them one or two health points before killing them. Remember that Sprawl (for now) is a hack from Apocalypse World. You may need to skim there first.