Try this site, it has a number of links to different recumbent manufacturers. They mention a company called Draisin that specializes in special need bicycles. I'm not a recumbent rider so I may be underestimating the problem, but I don't think your requirements would be difficult for any bike company or store to meet. Do me a favor if you would please, drop me an email if/when you find a solution. It might come in handy in the future.
