John,
You might try giving Emerson Motorsports a call. I live about 1 mile from his shop and he custom builds cars to fit any person. I know of two people so far that are larger than you he has built cars for and they can get in and out easily. One weighed around 350 pounds and another was about 6' 4" and I think he weighed over 200 pounds but can't say for sure. He could at least tell you what to do about getting a car that you car use. Also D.V. who is very active in this club would be a great source to talk to and he is closer to you than Emerson.
Ron
