>>2863492They're called PC connectors, and they have been standard for literally like 100 years. The same little round socket on your Zorki is the same one you'll find on any other camera or flash. Which is kind of unfortunate because it's a pretty shitty delicate little connector, but at least it's standard.
As for the flash, you don't need any fancy automated TTL features or anything like that, so any flash you can find for cheap that makes bright bursts of light will do.
