a good option for you might be a completely rigid 29er (a mountain bike with 29" wheels instead of 26" wheels) such as the surly karate monkey.

http://www.surlybikes.com/main.html

with that bike you have alot of options. for example, you can run skinny, 'cross tyres and have disk brakes, which would be good considering you are a larger rider. also, you can set it up with any type of gearing you want, which means you can optimize the gearing for your riding area, and you can use flat bars, drop bars, bullhorns, basically anything you want!