Herman,I am assuming here that what you want to achieve is better performance in fairly extreme terrain (if not, you don't need such a big lift). If this assumption is correct, then I want to state my contention that articulation is the most important factor.
Articulation, at least on the rear of the patrol, is limited by the length of the shock and the anti-roll bar (or stabilizer or anti-sway bar or whatever you want to call it). Thus, get quick-disconnects and also evaluate the shock's travel as part of the decision-making process. If the supplier can't give you the shock's travel, walk away as he doesn't know what he is doing.
I would also be inclined to recommend that you look at double-tube shocks or even at shocks with external reservoires, as all things being equal those will give you more travel...

Mag ons ons kenniskry met lekkerkry aanhoukry.