Well in the US anyway, reflex cans are pretty common in the UK. SA, NZ.
Not sure there are any titanium reflex cans in NZ - and certainly not at 8oz. (If there are any ti OB/reflex, please let me know!)
Aluminium (Hardy, DPT, ASE, etc), yes. But Oceania Defence (ti cans) don't do OB/reflex, unfortunately. And the aluminium cans from the others are moderately heavy.
I have OD cans, but am not overly impressed by either their noise reduction or the sound. Not super impressed by Hardy or DPT either, for the weight. Planning on experimenting with some of the Euro cans such as ASE, but, again, I think they're all aluminium (some with steel tubes).
The irony is that a few years ago, I tried talking Oceania into marketing their cans to the US, using Unknown Munitions as the distributor ... then UM went and started making ti cans that are superior to OD's cans ...