Since you stated you are in Bulgaria, I have no idea of what is available to you (and certainly not at what prices) so unfortunately no suggestions.
Why not take this time to improve your build? Most all prebuilt ebikes and pre assembled motor wheels are made with poor quality rims and spokes. At this point you can rebuild with better components.
Bonus:
- Better reliability
- Better performance
- Better riding experience
The best (performance and reliable) spokes for most of us are these:
https://ebikes.ca/spcust14.html
My rim cracked and I rebuilt it myself with no previous wheelbuilding experience!
See here:
Crack developing on ebikeling rim sidewall-- need to repair
Tutorial videos that should answer most of your questions:
Wheel Building - Getting Advanced - Resources