Just to clarify:
Longer shackles do NOT put more pressure on the leaves and cause them to flatten.
That is a misinterpretation of an (OLD) jeep, etc, problem, when the shackles were TOO long, and, not because they put too much pressure on the leaves (Which violates several laws of physics), but because over compression with too long a shackle can REVERSE ARCH the leaf pack...which IS bad for them.
The normal lift shackles for the X's are ALL too short to allow reverse arching on compression....so for the X, its not a problem.
Also, the lift shackles (They come with with reenforced braces, etc), are STRONGER than the OEM shackles anyway, and are LESS likely to break than the OEMs.
A suspension lift does NOT make more room for larger tires, except at ride height. If you brake, turn, go over a bump, etc, compressing the suspension, the tire will hit whatever it WOULD HAVE HIT without the lift.
A BODY LIFT is what makes room for larger tires. (Or removing the fenders or other parts that hit, etc...)
IE:
285/75/16's will fit, with no lift...and adding a suspension lift will not make more room for them. They are also a better size off road than the size you mentioned wanting to use.
Longer shackles ride better, and work better off road than AAL.
AAL stiffen the pack - which is sometimes needed for towing though.
If your priority is the towing, then the AAL is fine. AAL rigs often handle flatter than the longer shackle rigs, as the shackle rides softer than stock, but with the same lean in turns as stock. AAL rigs, due to the stiffer packs, tend to ride harder, and tend to lean less than stock.
The stiffer pack flexes less, so you have less wheel travel/articulation. This makes you more likely to lose traction off road.
Longer shackles increase wheel travel, as the longer shackle can swing inwards more, so you have more traction and more articulation.
If you want to maximize off road performance and ride, the longer shackles are better.
There's no wrong answer, its up to what works best for you.