With any trip, I would bring the film I needed with me and only use local stores as a backup in case I needed to stock up. I just came back from Barcelona, which has multiple film shops, but most did not have what I needed - some only had Fuji films, some only had 1-2 rolls of the emulsion or speed I was looking for, so I ended up getting a mixed bag of film, some of which I've never shot before...plus, I was out the time going to look for these places. It's been a while since I was in Vietnam, but even with more recent trips to Cambodia and Thailand, I brought everything with me from Japan.