Depending on budget I'd suggest Mela Purdie. It's on the more expensive side but the fabric, cut and drape are lovely. The Ever by X one dress project uses a similar fabric to the Mela Purdie "mache" fabric which also drapes well and is lovely to wear. I'd also suggest looking at Sacha Drake. Sometimes I don't like the fabrics as much but the dresses are cut really well and they give guidance about which garments would suit which shapes. I recently discovered Commonry. They have some great pieces and do a wide range of sizes. I've also bought clothes from Styling You the Label which have worked quite well. This label does more of a "capsule" collection but will occasionally have naxi dresses. I recently bought a black knit maxi dress from the Ark and the fabric iand drape are lovely. Finally, I really like some of the Johnny Was dresses. It can get expensive but the US website currently has a sale and, I think, will ship to Aus for $50. I'm not sure if that's AUD or USD