A heavy horse braided in colourful mane and tail flights, walking with the funeral cortege would give a sense of something special, a je ne sais quoi.
Gentle giants, graceful yet elegant, either of my mares are experienced in showing. Mature in manner and quiet in demeanour, perfect for the respected solemnity required for a service of this kind.
I have Queenie, a black mare, or Lunar, a bay mare available to walk with the cortege. Make that last march memorable!