UPDATE: Reviews section refreshed, redesigned, searchable: Go take a look
High back over low back. I have a low back (Ikea chair) and it is not good for my shoulders.
I should look at what my office has just bought for the transit rooms. They are actually really comfy and have good support. If I find out i will let you know.
High back, well cushioned and robust.
Personally, I have Giroflex G6 that I picked up on lockdown. It's ugly but it's super comfy and deals well with my arse sat on it for 8 hours per day.
Worth searching the forum for this, there's a number of long discussions.
Given your desk, I'd look at chair width - anything with arms obviously won't get you that close in to the desk. I went for a cheapy Ikea office chair, which comes with or without arms; it's been pretty good for the last 8(?) years!
