Hot Milk (google hotmilklingerie) have stunning maternity bras but I don't think they make crop tops. Check out their website and go to the stockist section - there are quite a few stockists in Melbourne.

I've bought mainly Berlie bras. They're far from exciting but they are comfy. However I think they only go up to an E cup. Really, what are the maternity bra creators thinking? Surely they know woman get BIGGER during pregnancy!! Good luck with the hunt.