As someone who has an AC, I have 2 thoughts.

1. It’s not useful for summer, I have never used it to cool a room, opening the windows works fine.
2. It is cheaper than a normal heater, and works slightly better in the earlier months of winter. Right now, it is too cold outside for it to work at its best efficiency, using a normal heater is better in this case.

We had ours installed back when the price of gas from Russia skyrocketed, it was way more affordable to use it for heating then.

Akko has good ones. They are relatively cheap, but expect to spend ~90 euros on a full sized 110 key keyboard. I like akko cos they genuinely look good, no need for RGB.