Why not the Panache from Rob Macks, LaughingLoon. It´s a very nice kajak and I think that if you ask Rob he will customize it for you.
Other choices are the Najad or the Nomad from Bjorn Thomasson. http://www.thomassondesign.com/edoc/enajad.php

At the studycircle I run last winter two Najad´s were built. One of the builders is a big guy too and he is very satisfied. We put on a little extra height to the foredeck for his feet. An alternative adjustable footrest/pedal-contraption was mounted and functions very well.
There will soon be pictures and a story about this at my updated site.