By Silver Age, do you mean the actual Silver Age Superman comics of the late 1950's to late 1960's? Or just pre-crisis Superman comics?
The the actual Silver age, I would strongly suggest the great Showcase Superman volumes, they are your best bang for your buck and pure silver age.
For color, Superman in the 60's. Skip the text, since it was written when DC still hated anything classic it's amazing that they even released this during this era.
There are two different Silver Superman Archives and a neat Silver Age Supergirl archive too. These cost the most.
The cheapest way to read silver age Superman comics is to start here at this very website!
1st read this to understand what is what:
https://www.supermanthroughtheages.com/a/comics.phpthen read the comics:
https://www.supermanthroughtheages.com/a/tales.php