If you're specifically interested in getting these items on the Cyseal map, you should check Conrad and Cylia every time you level up. In fact, I tend to buy most of these even if I have no immediate use for them.
I think their items are random apart from the leveling and the rough categories (say Cylia and Conrad always sell ingredients but the rest of the merchants in Cyseal do not). Of course you can always use a mod.
