Hi Michael,
With reagrds to your query.
64-BIT UNICODE, EXT - Non-unicode
64-BIT and EXT 64-BIT UC. - Unicode
Please login to your server and as it's windows please open run prompt and type disp+work or you can also login to sap \system \ status up there it will should you whether you system is unicode or not
If it states Unicode System (YES) then it is unicode, click on arrow showing right and will show you the exact release of your kernel and version.
Depends on that you can download saposcol as per your requirement.
Hope it helps.
Regards,
Deepanshu Sharma