There's a guide floating around to help you figure out if the rim/tyre combo you want will work with your liberty.
http://legacygt.com/forums/showthread.php/faq-offsets-sizes-rims-and-tires-gt-xenonk-version-4426.html
At stock height those wheels will poke out a fair bit, others on legacygt have lowered their cars on those rims and just had to roll the fenders + run camber to be able to fit them.
http://legacygt.com/forums/showthread.php/official-wheel-fitment-thread-182819p2.html
Check out that link and look about 1/4 of the way down the page, there's a chick running XXR's, and it details her setup.
Good luck to you dude