The scope you are getting has 68 MOA of adjustment, so if you mount it on a 20 MOA base that'll start your zero out lower in the adjustment range. Then you'll have more elevation for the longer ranges, and less travel below the zero point to confuse you on revolutions. Watch the lines on the turret like crow sniper said and you shouldn't have any problem.
The turret on your scope shows 12 MOA per revolution, and it should take you about 28 MOA to get to 1000 yards with a 100 yard zero, so that's about 2 1/3 revolutions.
