I am in the US in California and I believe that Rhus integrifolia is considered a native species here. Check out the Las Pilitas Nursery website (www.laspilatas.com.) They have lemonade berry and many other native plants and their website says that they ship worldwide.

Even if you do not want to purchase from Las Pilitas, the website is very interesting. Our climate zones are probably somewhat similar to yours.

Best, Shadow's Mom