My favorite sportsbras for large chested women (which I once was) are the Moving Comfort bras, specifically the Maia:
http://www.amazon.com/Moving-Comfort...ort+sports+bra
It took me only two, three weeks of core work to start to see significant improvement.
There are a few guys here who have had numb hand problems, maybe they can chip in and talk about their handlebar solutions. I know for me bar ends did not work, it felt like my arms were splayed out too wide on the bar ends. But others love them so they really seem worth trying.