I use an 1zpresso K Max hand grinder https://1zpresso.coffee/k/ works brilliantly for single dosing. The K Max is best suited for filter grinds but does a v decent espresso grind but does not have very fine adjustment. In my experience of looking at the single dose machines it is hard to get one that is not either espresso or filter biased. The Niche Duo might solve that but it will be more of a faff and also does not seem quite as well received as the original model.