I tried to get the N550i (well N22i, European, non-Chinese support version of N550i) data cable from the vendor the below images are linked to, when I was in Paris. However, they didn’t have any stock and I got a refund.
I am still very keen on grabbing the N550i data cable, and additionally the N630i cable.
If you know of a vendor in Taiwan, or even on mail order across the pond in the mainland/HKG (N630i also sells as the non-iMode N8 in HKG), I would be very appreciative of your assistance. Even if it is to just post the Chinese characters for data cable to copy/paste into a search.