I am about 6'4", the same 32" inseam as you, and on a dress shirt I take a 38" sleeve length. I weigh over 360#. Moth the Giant Suede and Giant Sedona fit me well. I liked the feel of the Sedona more than the Suede, but that is personal preference. (The Sedona also cost less and offered more for the money.)
I cannot speak to your special needs with your disability, but the base price of the Sedona at my LBS was $399.