Try Preston Market. The out of date/out of stock re-sellers sometimes have bags of boiled lollies that are perfect for stained glass bikkies.

EDIT: or make your own. Boiled lollies are just sugar and water boiled to hard crack stage, then coloured and set. I cup of sugar+1/4 cup of water is a good base mix. Boil up to hard crack stage, then dip out a half ladleful, add food colouring to suit, stir with fork and pour onto a tray lined with baking paper to set. Dip out some more, colour etc until you have all the colours you need. I recommend banishing all pets, kids and spouses from the kitchen until you've finished. Hot sugar is nasty when juggling priorities.

And the final result is easily storable in airtight jars/bags for future use. And you're going to smash it up anyway so if bits stick to each other that's fine.

Woolies used to have own brand boiled lollies but they’re gone now. Some locations have swanky kinds in jars but too expensive for cooking with