Hi there!
If you have the $$$, check out this link for some ideas:
http://www.supersizedcycles.com/site...67/page/837988
This link also gives you a source for properly sized bike clothes, should you get inspired and want to wear spandex and all...
Another option is to try a dedicated bike shop near your home.
But, in my husband's opinion (and he biked across Canada from Vancouver to Halifax two summers ago, with a larger friend), the most stress on your bike will be on the tires and wheels. If you are recreational riding, a regular bike should do you just fine (you aren't all that large, anyways...). Just make sure the bike tires are pumped up properly, and keep it maintained properly.
Have fun!