FIrst off, Listen to Jim and Grimm. Both have spent quite a bit of time looking for the appropriate combos that will yield the most travel.
Next, listen to Chris here...\
Don't chase a number... .in most cases, people end up spending a ton of money for not much more performance.
I will also tell you this, Jim at one point was running around in his SHort Arm XJ with maybe 9" of travel with his 11" Fox 2.0's, and he could probably run as fast as anyone would ever have the balls to drive a non caged XJ....
Moral of the story...... a number is just bragging rights. 9" of controlled suspension travel is 1000x better than 12" of non controlled. The bigger question should be going after the appropriate valving and cooling of the shocks!