A lot of people recommend Mtech (https://www.mtecbrakes.com/) and Zimmermann (https://www.otto-zimmermann.de/en/). You will of course always be able to find people that have had a bad experience with cracking discs an so on but after researching extensively I find these two brands to be great value for money.
I will change my front discs to these Zimmermanns: https://www.autodoc.co.uk/zimmermann/7517740
Oh I Almost forgot, the OEM Clubsport discs are also an option although a bit more expensive and not directional (which I do value tho): https://www.awesomegti.com/shop-by-...lubsport-s-front-brake-discs-pair-5q0615301c/
I think I will go for the zimmerman's
You can see the brakes in this thread: https://www.audi-sport.net/xf/threads/upgrade-oe-front-brake-discs-340mm.238613/