Alot of bikes will take your weight. I weigh alittle more than you and ride a Giant Cypress DX and just bought (1/2/12) a Cannondale Cyclocross bike. I did have spoke issues with the Giant but only after 5 years of riding. I rode the Giant across Kansas in the annual Bike Across Kansas event - 500 miles in a week. The bike performed well even though its not designed to be a touring bike.
Here is a list of things to remember when looking for a bike:
1. The first bike you get probably will not be your last.
2. Front fork shocks can be scary at our size. I locked my Cypress forks out to try to avoid the problem.
3. All seats may be uncomfortable for a period of time. A big seat may look comfortable but later you may go the other direction.
4. Alot of people here started with a used bike and got their feet wet so to speak.
5. Multiuse paths are a fun way to ride without the worry of traffic.