I am not sure if Toyota sells the bumpers separate. All you really need to do is replace all the window guide bumpers. They get hammered on and slowly smash down. Age also plays a role, they get brittle and shrink slightly creating slack. I would try Toyota first then looking around EBAY or a junk yard. Gather a bunch of the better condition bumpers and go from there. Good luck.
If they are loose the way I think you are referring to. Take off the interior of the door. Then you'll see a few metal guides with cloth covering them to hold the window in place near the top where the glass comes out of the door. Try loosing the bolt on the guides then move them as close to the glass and see if that helps.