Im a plus sized girl in Aus with the opposite problem - huge breasts, smaller stomach, so I can symathise. My stomach can still stick out if I put on weight though (I noticed this a while ago and it inspired me to lose weight after I thought I too looked pregnant). I found that some gathered shirts around the stomach really help. I buy alot of my things online (since you dont have many shops near you) at www.bigcitychic.com .au
(check out their cutie 3/4 length shirts and youll get what I mean by gathered). They have shops too but now that I know what suits me I just get lazy and buy there online. I love this shop. I also buy alot from the Sara line at www.ezibuy.com.au
(they are also stocked at David Jones stores). Myers is also a fav, but can be very expensive at times. I've found these 3 sites/shops really helpful and they also stock younger designs which is great. Hope you find that helpful.