Cocogarden Cocopeat Brick - Expands To 3.5 Kg Powder This is as good a place as any to start. Carnivorous plants don't need a lot of medium, so this should be plenty to get started.
Trust Basket Cocopeat Block - Expands To 75 Litres Of Coco Peat Powder ,Brown This is a bigger brick. Probably better if you also grow other plants in containers. Works out cheaper.