You have to be 100% sure they have never used pesticides on the plants because it can be harmful to the reptiles if they nibble on them. Everywhere ive found online cant be sure they havent used them, i know someone who put plants in with a pair of chameleons the plants where reccomended in a chameleon book but the pesticides killed them
If you find anywhere though, let me know as you cant beat live plants imo. Where abouts in Manchester are you? Cockbrook farm in Ashton sometimes have organic plants in.