Which region-free 3DS eShop countries exist, assuming they do?

Continued on from my previous question, I ultimately deleted my 3DS NNID and decided to recreate it under a different region [which will have to wait until my birthday due to parental problems]. The thing is...which eShop regions can be funded with foreign credit/debit cards?? I'd like to get a full list of the region-free eShop countries before recreating my NNID, because once I set my mind on the country, I can't change it without deletion or reformatting [which is the reason my old NNID got deleted].
P.S. I'm mainly doing all of this to get 3 eShop-exclusive titles that I especially want. They cost about 31.97 USD in total.
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