How about a mirror?
Do you have a cab? My concern, as I do not have a cab, is viewing a monitor in bright sunlight?There's a classic thread here on TBN talking about a 'backup camera for $50" or something like that. Do a search, find that thread, and read it -- lot of great information. I have front and rear cams on my tractor and they are very handy at times.
Here you go, grab a beer and read away:
https://www.tractorbynet.com/forums/customization/316927-backup-camera-50-a.html
This was my first thought. But I can't find an option that would work very well to let me actually see well what a given implement is doing. Where would you mount it?