That is how a lot of the upper level coilovers work. On mine, the bodies thread into the lower mounts for height adjustment without detracting from the stroke. The fronts have an extra inch of adjustability because the lower mounts have an adjustable heim joint. The lowest I have taken my car was 10.75" in the front. I figured I had another 1.5" left. I measure off the pinch welds now and the car is higher that that now.
You would do your rear suspension a huge favor to run taller tophats in the rear with your current setup. slamming the shock bodies into the bumstops when they bottom out can damage them and cause them to leak.