Almost ready for conversion, rear brake questions!

[willo]

Ok, I've got a set of spindles, arms and offsets for my frontend - spindles and arms are from a 98 MZ3.
For the rear, I picked up both brakes/arms+axles from a 318ti.

I'm concerned about the rear brake size compared to the front M3s.
I found a post or two on a 318 forum suggesting that I could use e46 rear brake calipers/carriers and rotors to get near M3 rear brakes for a fairly close balance. Can anyone confirm this before I go parts hunting?

I've got brand new M3 brembo rotors and pagid pads for up front. :)

[Aptyp]

simple answer: you can't

you'd need caliper brackets to be custom made and e46 rotors aren't deep enough to go on 318ti hubs and still touch parking brakes.