We have a small number of Perch available. 

These are not something we have very often but get asked for a lot so I cannot see them hanging around long.

Being a carnivourous fish we would not recommend adding them to your Koi or Goldfish pond as they will most likely eat anything that gets in their way.

Perch like weedy sheltered places to lurk/hide to stalk their prey. So they would certainly require a more specialist Pond/Tank setup.