Headrest option is a $99 add-on.
Shipping is free, excluding WA and TAS.
Thanks to chess who mentioned this chair in the Secretlab post. Probably a better option if you can stretch the budget a bit because of the mesh back which will be cooler and more ergonomic shape. Unsure of how it compares to the Ergohuman chairs.
I got the ergohuman v2 yesterday and I'm pretty happy with it. Very comfortable, adjustable and the mesh is ideal for the heat