John,
You might try contacting Bill Emerson of Emerson Motorsports. I know that he has built some Cobras for guys as large as you and a little taller and they have no problem getting in and out of them. I am not sure of just what all he did but the seats were one of the changes along with some others. I am pretty sure he has a link on here in the builders list.
Congratulations on finally getting your dream car.
Ron
