Where can I get JAL PAI files?

Go to www.projectai.com. First, look under PAI Libraries and locate the JAL planes you want, and download those. Then go back to the top and look under Certified Resources to get the aircraft models for the planes you've selected. It takes a while at first, because the site is organized by aircraft type rather than airline, but I usually end up finding a few other interesting liveries so I don't mind browsing.