Based on your question, the Dulux Veldstorm 20L paint seems like a great option for your needs. From the PriceCheck search results, the Weatherguard Matt Veld Storm 20L (Product Code 5301038) is available for R3634. This exterior paint is made by Dulux, comes in a 20L size can as you requested, and has a weather-resistant matte finish suitable for outdoor use. Let me know if you need any other details on this product or have additional questions!