My friend, as someone who has been known to spend hours researching the most up-to-date Libs versions (it's part of my OCD), allow me to introduce you to this site:
http://amiga.foul.fr/index.php?p=Work%2FLibs
Also this list was helpful when I was first getting started.
You can get partial version info from SysInfo, however speaking from experience, the C:Version FULL command is going to be your new best friend. 
I run modified libraries from THoR, Cosmos, and Peter K., among others, and definitely recommend them (am sure someone will chime in here about "blah blah unstable, blah-blah not Commodore original, etc." however they work fine for me... your mileage may vary ).
Also if you would like to compare version numbers of specific libraries, I am down for that game any day. 
No, his new best friend will be VersionWB:
http://aminet.net/package/util/sys/VersionWBThis makes it easy-peasy to check any file version. I personally have it set up in my Tools menu on my Workbench. All I have to do to check a file is select it with the left mouse button, then go to the Tools menu and select 'VersionWB' - it then brings up the version info in a neat little dialogue box. And if I don't select a file and I go to Tools and load 'VersionWB', it brings up a file requester instead, allowing me to check any file, anywhere.
Neat little program. Yes, possible with a bit of AmigaDOS scripting, but why bother when there's this?
Try it...you might like it.
