As far as which shoes: whatever you pick, test in advance to make SURE you will be comfortable walking in them for long periods. I still regret missing the Imperial art gallery in Vienna because the boots and shoes i packed were not as all-day as i assumed, and my feet hurt too much.
As far as your poison eye goes: that is of course subjective, but also tends to be very fickle. I have travelled, in the remote past long before fashion sneakers were a thing, in parts of the world where it seemed perfectly natural to wear sneakers with a dress; I saw other people doing it, it was comfortable and practical, and soon I found myself doing it without a second thought. And weeks later I have been in urban settings where it was hard for me to believe that I had ever worn sneakers with a skirt.
So I would suggest 2 things: One, dig up and immerse yourself in some street style photos from the places you will be visiting. Two, find some comfy sneaks and actually wear them in an outfit a couple of times, even if you never go out of the house. That will give you a chance to train your eye and see if you can imagine being comfortable with this look.
The kind of sneaker matters, so does the kind of outfit. I am happy wearing white or colored sneakers with a dress as a semi-casual summer outfit (so, work or church). With pants it's harder for it to feel anything but super-casual. And I don't own black /dark oxford-like sneakers, because I'm always in boots in the winter, which led to the problem in Vienna (so, I guess I discovered a wardrobe hole that will exist if I do more travel in Europe /more temperate winters.
