Years ago I bought an automobile seat from a car mechanic that was selling a car for parts. So I got a Mercedes seat. I've been super happy with it. And it was super cheap. Just needed to be plugged in and adjusted since it doesn't have manual adjustment. But these seats are made very comfortable, so you don't get tired even in long travels.
Of course, no seat is going to compensate for an unbalanced life. Regularly getting up through the day, and having days off with going out and having good physical activity seems like a part of it.
RE: Heavy User... Looking for Ergonomic Desk Chair!