Wishlist: Percussion Features

Starting a wishlist of things I discovered I need / will need at some point:
Bowed cymbals
Timpani with cymbal (bowed / unbowed?)
Pedal glissando for cymbals?
Motor speed for vibraphone
More mallet options, including yarn vs resin mallets (correct me if this is already handled...)

A notable use for these features is Apparitions by Brian Balmages, where all of the above are employed to add to the atmosphere of the piece