Hi,
I stumbled on the Breast Vest, on ebay. It's like a tank top that you wear under your normal tops and it sits just below your bra. So you can lift the outer top up and still have your tummy covered. They're in black or white, about $20. I've been using them ever since I found them and haven't had to buy any other 'feeding tops'.
I think the company selling them is called Quirky Bubba or something and they're based in Vic.