There might be divergence in this thread...
i) How to store notes safely....
ii) How to display notes safely....
While I think there are plentiful options for storage that is all your personal choice in the end as to what you can afford and what you're willing to do.
With respect to displaying notes.... My opinion has been and will always be that papermoney IS art! It should be displayed! Now go to places that display art and important paper documents and find out HOW they display their works of art. Direct sunlight is definitely a no no. Moisture is also a big issue as you don't want foxing or mould to start to form on your notes.
I am in the process of renovations but eventually when things are done.. one of my "hobby projects" will be to construct a picture frame that I will be able to interchange the note to display a different one regardless if it's one of my graded notes or not.
I will be honest I don't know what light is best but I use LED strip lights.. The reason I like LED lights are they emit little to no heat.
If you're using a display I would also recommend you have a cover the display so the items are not always exposed.