We probably need an edge cutter / grass trimmer for the first step. One of those long ones, either with a line or Einhell also has small plastic blades. However, they wear out quickly and are expensive to replace. So probably line.
We once had such a device with plastic blades, never again. They wore out super fast and the plastic then lies in small pieces in the garden. Microplastic in the lawn... no thanks. After using it twice, we switched back to line and now have a thick power device, I should check which brand, it works great. Better to size up than have to buy a second device later because the first is too weak. Both for the battery and the power.
Regarding battery systems, we have Makita, Metabo, Wolfcraft and I think at least one more. All mixed up because we didn’t think about it at all - probably smarter to buy one system and stick to it ;)
Overall, we have also experienced that it is better to buy something a bit higher quality (=more expensive), otherwise you get frustrated after a year, put the device aside and then buy a replacement in "better".