This is all resource that I use for customizing KDE plasma with Unique layout, this setup using latte-dock for panel and dock. For theme I use relax theme with blur transparent and use several plasmoids widget as I mention on latte-dock layout. you can download latte layout for this setup from link below.

Download Latte-layout :
https://www.pling.com/p/1981573/

You can follow the step-by-step how to make your kde plasma like on screenhot above from my video on youtube :
https://www.youtube.com/watch?v=ETJeeBlCZBE

I also make documentation for this cutomization. So you can copy paste the command line that I use on the video. The documentation support for Fedora, Debian/ubuntu and ArchLinux/Manjaro.
Download Documentations:
Documentations - Make KDE Plasma Look Better and Elegant