I have run the Z04 with my 4 pads monoblocs. £450 a set!!
As a consequence i have looked into alternatives too.
I still like a lot the MCR from Bendix. Equivalent in the dry to be honest and about a 4th of price. Brembo only edge them in cold performance and wet performance.
I have not tried but Performance friction is said to be very good too. About half price to Brembos. Apparently Bayliss used to use Perf Friction.
And i do run the 6mm discs.