This is the bracket you need.
Made of aluminum alloy, precisely designed and machined here in Solcal, USA
Brackets may be made available for separate purchase (depending on how many people are interested.)
Multi-sourcing retrofitting may work and appear have some money saving advantage but is not always the best, for example M5's 400x36 rotor & pad size can be overwhelming for 5 besides you should also consider future maintenance/replacement, you must replace the whole rotor assembly and the brake pad is not cheap either.
We are preparing to offer a complete brake kit properly designed with our light weight two piece rotors, the rotor replacement ring is cheaper, so is the brake pad (standard FMSI)