I've not looked for a while but Lazada used to have loads of farang stuff, make sure you look through as I've seen the same product at different prices,
We have a couple of shops here in Phuket that ship all over Thailand, and Tops have a range of things,
My wife walks around Makro with the Tops app open checking the prices, Nescafe was cheaper in Tops than Makro, last week 555