Whatever you do in the front shouldn't affect the height of the rear at all.
From what I read, in the front you install the shock simulators and with the wheels/tires you want to run, you set the simulators to one of their three presets which emulate the three most popular shock body lengths. This is the length of shocks you order. Simple.
The spring is then chosen by what lb. rate spring gives you the recommended amount of sag when laden.
That's it. The rear end is not involved whatsoever.