Hours of work, finally done Special thanks to @miishb79 & @Jacob Low for the inspiration and your templates!
I build a 1024x600 Screen. Blue like my LEDs in the Tower and found a nice screen on Amazon. i used some cords to attach it under my monitor (total professionell ). Fun Fact. I'm using a HDMI Switch. For my Gaming PC it's this Screen and for my Work PC I see my next Meetings, ToDos and the weather (with DAKboard.com).
Thanks for all the ideas and help!
Daniel / Private Joker