In the same vein, a Kinesis Advantage keyboard. I bought my first one fifteen years ago and now have two more. As a software developer, I do a lot of typing. It took some time to get used to the unusual form, but it was worth it.
Different chair, but similar experience. I got a used Steelcase leap v2 from a refurbishing company, and I absolutely love it. Used frame with upgraded hardware and new upholstery for about half of MSRP. Had a few scratches but otherwise looks like new.
If you are ever in need of another, Crandall Office Furniture is 10/10.