The YJ hasn't been manufactured for several years now .. so the chances of getting a new YJ is slim. That being said, my Dad at 6'2" has no problems fitting into my Jeep and sitting comfortable.
If what you need is a longer distance between the seat (as far back as possible) and the steering wheel and gas peddle .. you could make a flat-bar adapter out of 1/2" steel plate that you could bolt to the floor and then bolt the seat to the adapter and move it back an inch or two to make it more comfortable for yourself.
The only downside to doing something like that is the people in the backseat might not have enough room for their kneecaps
Hello, my name is Vance and I am a Jeepaholic.
Its better to be naked with your friends, than to be clothed with your enemies
Silver 2006 TJ Unlimited
, zombie ready as the daily-driver