Trying to find ergo chair—very short notice

My job has given us until the end of today to provide chair choices. The problem is that I CANNOT find a chair that I think might fit me.

Knee crease to floor height 20”

Knee crease to backrest 25”

Hip width 16”

I have been using a chair that’s 20” wide and that’s WAY too wide and I have to splay to use the armrests. I think I need an 18” seat but I can’t find one anywhere. I do need armrests and just generally more support.

I was given a budget of $200 but I don’t know if that’s realistic. If absolutely necessary I will purchase a chair myself and spend up to $500. I’m a taller woman (5’8” but very long legs) and I live in the US.