Springs are not the same as spacers. Springs will change the ride. I would not personally recommend a spring change without the a matching shock change.
If I were you, I would do the "on top of coil" spacer lift with an AAL as you first suggested. It is easy to remove if you hate it and it a very low upfront cost. Plus you can sell them pretty quickly on the forums. Then, if it ignites your addiction to modifying the X, I would read as much as you can about the options and opinions on the available lifts because they are all a bit different and depending on your personal goals and tastes, you may decide on a different path.
I think the PRG kit is better then the Nisstec kit only because of the AAL. PRG is sometimes slow to ship and can be hard to reach, though.
If you are ready to part with a bit more coin, the OME, PRG Advanced, Nisstec MK84 Extended Travel, or NissTec Radflo Extended Travel Ultimate Kit are all great kits and it is hard to go wrong. The only caution I have is that a 2011s rear springs are probably starting to sag so an AAL might not work as well as you expect. Read up cause I am just some crazy guy on the internet...