Or plug the part numbers into Amayama or Partsouq to find out about availability and pricing. Sadly (at least here in Australia) parts are generally a lot more expensive going direct through Toyota. Why Amayama, etc. can supply them significantly cheaper in most cases isn't something I'm privy...
All 1hz/1hdt stuff should still be available as those motors (at least the 1hz) are still in production. It's interesting to hunt for parts through Amayama as stuff I would not expect to find is available, and stuff I expect to get isn't. And wierdly enough, most of the odder finds are in the...