My wife got her 2nd BA in Nov 2007 to Mentor 800cc Silicone Gels. She is 5'6" and about 135 Lbs. We live in a very small town, about 12,000 I think. She gets some looks, but she hasn't had any bad experiences so far from family, friends or the town in general.
She too would like to go larger. She is thinking of 1200-1600cc. The only thing hold us back is we are still paying off the Nov 2007 surgery and then we need to save up some money again before the 3rd BA. Also, at that time, we seem to have exhausted our local Dr resources and may have to go to CA for a Dr that is experienced with such sizes.
I think the most important thing is sometimes the most obvious. Just to feel comfortable with yourself. Which after any Plastic Surgery or other major body change, can take some time. And during this time adjusting to your new look, your perception of how people view you are likely distorted and amplified.
More forward with your plans if it's what you want. Thinking more about how others will view you, will just drive you crazy. We both though everyone would be a certain way when she got the 800cc Silicone. And now we feel like no one ever cared it ever happened.