Here you can see the result of the idea. To mount the backplate to the TV I used four M6x50 screws with some nuts and shims to fix the plate as you can see in the following picture:
On the backplate, I drill some holes which I used to mount the electronic devices with cable ties. This is a quite simple and easy solution but the result is astounding:
Everything is cleanly mounted on the backside of the TV. Further ideas could be to LED strips to the backplate to get additional illumination or light effects.