Recently, I've been a fan of the ATOTO S8 with the plug and play adapters for the BRZ, it makes it easy.
ATOTO S8:
https://www.amazon.com/gp/product/B0...e51723831ae0c0
Wiring:
https://www.autoharnesshouse.com/67122.html
This is highly dependent on your budget. More $ could get you a Pioneer or Sony that would be an upgrade from the S8