Use Nippon Denso W9EXR-U spark plugs.
The crush washer comes with the new spark plug.
The aluminum tubes do not have to be replaced every time you change plugs.
If the area where the spark plug goes through the bottom of the tube becomes tattered looking, replace it.
The square O-ring tube seals do need replacing more often than the tubes themselves.
Toyota part numbers for the items are below and are individual parts (1 tube, 1 O-ring)
Spark plug tube.....11191-76001-71
O-ring for spark plug tube.....80430-76036-71
And always beware, never add oil to the engine while the spark plugs are out. One of our guys did that ONCE.