I had the same problem about the J7 original seats. You do not even have to be that tall to sit uncomfortably in it. I personally have 3 problems with the original J7 seats:
1. You cannot push back your seat, enough to have your legs in a fairly normal position. If you're taller than 1,80 m (5,90 ft), you have to drive with your legs semi-flexed which for longer distances is terrible.
2. The position of the seat is too high. If you look underneath the seat, there are lot's of brackets on the floor and than the seat has it's own brackets that bring it even higher. You have under the seat a lot of wasted space. This means your head is significantly higher than your steering wheel, and you are always looking down, which is quite bad for your cervical vertebrae.
3. The seat itself is s**t. The sitting pad is too short to support your knees and the pad itself is very uncomfortable.
I remember very well driving for more than 2-3 hours and walking like an old man after getting off the car.
So if you try to adapt something to the original mounting brackets, you still have the problem of not enough push back and too high driving position. But, if you cut off the floor mounting brackets and fabricate new ones, you can mount your seat lower and you are no longer depending on the producer of the seat to have adaptors for the J7. Actually with that you can adapt virtually anything you like, also inexpensive seats that you may buy from parting out shops. I personally adapted VW Passat (or Jetta) seats for which I paid less than 100 EUR. They come with manual height adjustment and drawers under the front end, so really useful features.
You can check how I did it here:
Rejuvenation Treatment for Old Girl LJ73 / build
First page, the 16th or 17th post you can see the brackets I've fabricated by myself, and the third page how the seats looked like as soon as I remade the upholstery.
