Well the OP wanted a budget option... The budget options are EBC or APEC.
Zmanalex says APEC discs are "not bad" viewtopic.php?f=59&t=43084&p=635371 but I don't know anyone with them fitted to a Z.
I will need new discs soon and would also like to hear what is put there at different price points.
I had a forum members Zed in for a brake upgrade yesterday.
He went for DBA rotors front and rear with Ferodo DS 2500 pads.
The stuff that I removed were Apec Pads and Apec rotors and they were compleely destroyed.
The Zed is a heavy car and IMHO budget stuff just does not work and is totally false economy.
Most of the budget stuff suffers from excessive run out.
The installed runout of a rotor must not exceed 0.050mm.
Excessive runout will result in DTV being worn into the rotor within as little as 1000 miles.
DTV will cause pedal pulsating, steering shudder or vibration during braking.
There are lots of people who do not understand brake component principles and are unable to take good advice on board and consequently end up paying twice when thay have to get the job done all over again.
Alex