Yeah, also let me add the requirement that it can't break the bank. I can't spend 1k on a chair. Perhaps something more in the 120 or less range.
Although I believe you can get great chairs for less than $1,000, keep in mind that this is your spine we're talking about. If spending $1,000 prevents you from having to go through $50,000+ surgery and/or physical therapy in the future and significantly improves your quality of life when you're 70 years old, I call that a wise investment.
The same goes for mattresses. You spend 1/3 of your entire life on these things. You should be spending top dollar for the best mattress you can find on the planet.