I know I am late to the party - I haven't been here at all for weeks!
Like you, my desk is just a bit taller than the norm. That's bc we made it out of two "short" cabinets; each one has two shelves in it. Spaced them far enough apart for a chair to comfortably fit under and topped with wood.
After a couple of office chairs, both highly rated but not very expensive, I realized that I'd never get the height I need from a standard chair. I looked around and tried those that I could. It's really frustrating that, even before the pandemic, there are not a lot of chairs that are available to test.
I finally decided to get a Heavenly Sewing Chair with an extended cylinder and I could not be happier. You can customize them in many ways - extended cylinder, different fabrics, arms or not, etc. Yes, they are pricey, but it is so comfortable and supportive, and I can adjust to just the right height.
As a high school secretary, I bought a lot of chairs over the years. We moved into a new building, additional staff, chairs wore out, etc. I can tell you that the cylinder fails on a ridiculous number of chairs - it's probably the number one reason we needed replacements. I'd pay particular attention to that, and the guarantee.