I'm 6'5" and a slender 250 right now, but I used to weigh around 280. I use and Ameristep climber. It was the only one I could find with a 300# capacity. It is too narrow and uncomfortable to sit in for very long, but it gets the job done and I can get it thru thick brush where a bigger stand would be impossible. I have learned to live with it.
Face it, you are a big guy, and big guys have some things to deal with that the surrounding hobbits do not understand. We will never own small cars that get 40mpg, we will never be comfortable on an airplane, turnstiles hit us in the groin[:@], we will never go to a regular store and buy clothes or shoes, the bed will never be quite big enough, and for some reason, recliners don't last very long.