Have just ordered 3 big toddler dummies from this site:
MAM 12m+ (same as the 16+ in USA I believe)
so 3 types of size 3 soothers in one go.
I already have:
BabyOno 18m+ (only seen on Amazon, described as Mammoth Baby)
and if I get round to buying the Chicco 12m+ I have seen on Amazon and ebay, that completes the 6 size 3's available to us in the UK as far as I can find.