A good place to start for a lift is to decide what wheels/tyre combo you going to run. Then get lift to suite wheels.
From an old JP Magazine suggests that a good start for wheel choice is by wheel base of vehicle, and has a chart as follows;
Wheelbase (inches)_________Tyre (inches)
80-90____________________32-33
90-95____________________33-35
95-100___________________35-36
100-105__________________36-37
105-110__________________40-42
120-plus__________________42-44 plus
It does say this should only be a starting guide and adjustments to be made for budget, type of use and lift used and other adjustments to body etc may be needed.
Hope it helps