You don't need Prague powder, pink salt or any other so-called curing salt, just plain old salt and good hygiene. Same thing with salami's, bacon, lonzino etc. You won't poison anyone, but except HFW no (mainly American) book dares to leave out advising on so-called necessary additives out of fear of being sued, and the sellers play in on that fear. What is a must is a meat slicer - now that's something worth investing in, especially for air dried ham.
Re flies, cover any meat (not skin) of the ham with rendered fat, then hang in muslin / a cotton pillow case. A nice thick layer will be fine (much thicker than a cream you'd put on your own skin).