Funerals don't need all black these days but if you're looking for a "funeral dress" I don't think any of those are particularly funereal despite being black - especially the third one. The second is more something to wear in the evening when on holiday. The first one is the most "funereal". If you'd rather wear a navy dress, that's fine. A formal navy dress might be a better option than dresses 2 or 3.
I don't have clothes which I keep specially for funerals but I have a lot of formal clothes which are suitable for funerals. My go to is often a dark green lace dress with a black silk lining with black patent flat shoes and one of my black coats.
Not trying to be unhelpful but without knowing your budget or preferences there's an awful lot of navy wool coats around and googling "navy wool coat" brings up heaps of results- here's one but there's heaps from very cheap to several thousand.
Navy wool coat
So far as "flat dark shoes", again not trying to be unhelpful but without knowing your budget or preferences there's an awful lot of them around too.
If flat dark, formal shoes aren't something you'll wear often there's no objection to a supermarket shoe. Re the coat, I'd suggest the best you can afford.