Existing kit for a wireless bluetooth keyboard

Is there a getting started project for a battery powered bluetooth keyboard?

What I want is to have a device that can connect to Mac, Windows, iOS and Android as a bluetooth keyboard.

I’ve seen that I can purchase an Arduino with a bluetooth but I also see SparkFun has it’s own products with a lot of momentum behind them. What should I choose? I’m on Mac and have USB C connectors. What do I need to buy for either of them? If I attach a screen will it run a browser and connect to the web?