I dont know any reputable aftermarket just be aware that there is a big difference between OEM and genuine LR... i gave you the p/n for the genuine LR which i admit that seems very hard to find but for OEM(which doesnt mean too much these days) use AMR6103G and you'll find in many places even different brands. Leoni is supplier for BMW too so might be good enough
i dont know what you mean by audio

