If you find a E46 330i, you might also want to consider a full brake setup off this car: it would give you 325mm in the front and 320mm in the rear and it would be a bolt on swap...
Alternatively, 320mm rear vented rotors can be sourced off of an X3 (any model, old or new). As noted below, the X3 might not be able to provide you a full front and rear swap: the front calipers are the same as the E46 330i, but the caliper carrier has a different p/n.
In summary, 320mm vented rear rotors can be sourced from the following cars:
E46 330i All
E83 X3 All
(Quoted from a how to - big brake conversion)
Disks and callipers can come from the X3 but the carrier has to come from the E46 (or made up )
It was of a 2.0D X3 2006 and the carrier mounts are different to the hub carrier (wider). The caliper mounting distance is ok at 110mm.
They were in excellent condition as well
Pursuing some on E bay again
Thanks for the prompts. Working this weekend so contact punctuated Was going to update the forum with pics when completed.
Having a few other issues also with broken front strut pinch bolt to the hub carrier at presnt