RV Part Shop has a wide selection. If you don't see what you want, be sure to call them. Super helpful and can likely find what you need.https://rvpartshop.com/category/110-tubs-and-showers
We use an old school mosquito coil in a metal screen holder. It slow burns inside the holder and we clip it to the top of the dining tent just outside the main door. Does a great job!