the wire from the trem claw is a ground wire. solder that wire to the back of one of the potentiometers to ground it out. Since the claw is connected to the springs which are connected to the trem block which is connected to the bridge . . . this grounds your bridge. all trem-equipped guitars should have this, Floyd or not.
Duncan is supposed to include the parts you need whether you buy singles or a set. maybe someone that owns a Blackout set can chime in . . .
one of the pickups should come with an output jack I would hope. worth a call to Duncan if you're not sure. their customer service is pretty good.