Praesodymium, you get through mining. Either in a metallic or metal rich ring, pristine is best. Same with samarium, osmium, platinum, and bromellite, you can't buy them, they have to be mined. Icy rings for bromellite.I am still lost,, for example. I need " Atypical Disrupted wake echoes, Chemical processors, and Praseodymium " .. none of which I see on the list, nor do I see them in EDDB ... so just where do I look to find this stuff? Is there a site to show all the required needs for the upgrades?
The wake echoes, you get through scanning wakes, chemical processors from killing ships. Missions will work as well.