Have a look at jauce.com, but you should have a general idea what to look for. Dictum.com has a curated offer, but idk what shopping will cost you from Germany, but they for real quality. https://www.dictum.com/en/sharpening-e
And what you need depends on many factors: how many knives is worth how much to invest? I like that one for basic needs: https://www.dictum.com/en/combination-stones/cerax-combination-stone-without-base-10006000-grit-711547?c=12246 Of you want to sharpen Japanese steel, like shiro gami or aogami, maybe something with softer bindings, tiger stones for example. Chips in the blade? Diamond stone, only mono-crystalline ones. Here’s an inexpensive set I can recommen: https://www.dictum.com/en/sharpening-stone-sets/m-power-tools-dc-shapingsharpening-block-set-extra-finecoarse-740063 Maybe there were vendors for M. Power tool diamond stones in your vicinity.
To see that people actually learn during my lifetime. I won’t see the solution to all problems, but just signs that it’ll change some day.