I'm not using a drop axle, but I used a somewhat scientific method to determine my ride height. I put a beer can under the step, directly in front of the rear tire. If I crush the can down 25% it will fit under the bottom of the front fender ahead of the door. I'm using coilovers front and rear. I plan to use Google maps to locate speed bumps and plan my trips accordingly.
As for the power steering upgrade, I have no idea. Keep in mind, you can get a 2" drop spindle for those drop axles.