Hi guys. I'm getting a shelf mount monitor next week

This might be sort of a stupid question but how do I secure it to the cab ?
Do i just use bolts to secure the bottom frame to the shelf in my cab or do I have to build a wooden frame to also mount the side frames as well ? I want to make sure its secure.
I was thinking it may be easier to build a frame like the one below since the shelf in my cab is flat and I need the monitor angled upwards. Other wise i guess I wold have to make an angled shelf in my cab

What do you think guys ?
Thanks