Whatever chair you decide, make sure you sit in it first and can return it after a week if you find you don't like it. There are a lot of good chairs out there but whereas you may like an Aeron, many people will also do not like the chair because of where the posture fit lumbar hits their back. Same thing with a Herman Miller Mirra chair. I've never seen such a polarising chair. People either love it or hate it.
As for the OP's post, you really aren't going to find anything highly ergonomic with "professional stylish and ideally with leather. Bonus points for brushed/satin brass". You will probably only get height adjustment and an older style synco-tilt mechanism. Most of the major manufacturers have going away from this style of chair. Your best bet is probably a chair by Global (Canadian company) There are many deales for this in town but there is also a manufacture's office in town too.
https://www.globalfurnituregroup.com...gement-seating
Maybe National has something you might like too.
https://www.nationalofficefurniture....y-type/seating
Like I said though, most manufacturers are going away from this type of seating.
If anybody is looking for a high quality ergonomic chair, there are typically the models that get evaluated side by side on large tenders.
Herman Miller - Aeron, Mirra (cheper price point) and sometime Embody. (When I was at the Herman Miller dealer we almost never sold these because of the price and warranty issues.)
Haworth - Very Desk and X99 and Zody
Humanscale - someone mentioned it. This chair is a bit different because the seat is gel filled. It definitely "sits" different from the other chairs on this list. Again, a kind of love it/hate it type of chair. I personally like this chair with the head rest.
Steelcase - The top of the line chair is Gesture. Imperial Oil standardised on this chair at their Calgary campus and now throughout NA. There are some innovative features on this chair but I'm not going to get in to it. The leap chair is still Steelcase's most popular chair. There is a new chair out called the Series One. It has all the ergonomic features of the Think chair but at a price point closer to what Global chairs sell for.
If you are looking for one of these chairs I can probably give you a name of a person to talk to at the prospective dealerships. Remember also that every one of the major dealerships have a used department. It is much better to buy a used chair though them because you get the full warranty. Very handy if the pneumatic cylinder should crap out. Also, in times like now when companies go under, quite often we get their furniture back and then sell it off at a discounted price. One more thing, if you are buying a used Herman Miller chair make sure you know which size it is. HM chairs come in A,B and C size. Most people need a B size chair. For the Aeron you can tell by running your finger on the underside of the top of the chair back frame. There are either 1,2 or 3 nubs there which tell you the size.