You'll find a lot of lift kit info in old threads if you poke around. You might try 4x4parts or Rugged Rocks. I've heard little to recommend Calmini's customer service and can't afford their prices anyway. You'll also need to beef up your steering linkage to deal with the lift.
Bumper options are mostly roll-your-own at this point. ARB used to make a front bumper, but they're expensive if you can find them. KMA or TAG or whatever they're called this week made Pathy bumpers, no idea if whoever took that over does anymore. If you find a bumper for a Hardbody pickup, you'll need to modify the brackets to make it work on a Pathfinder. Many WD21s came stock with a spare holder that's actually pretty stout. They can be fitted to a truck that didn't come with one, if you get the bolt plates that go inside the fender and don't mind doing some screwing around to make them work. I'm not sure I've seen an aftermarket roof rack strictly for these. Some people have adapted the stock Xterra roof rack to fit. Others come up with mounts for universal racks, or, again, fab their own. I've seen some pretty good-looking racks made from EMT conduit.