What edition of Studio One are you running? In order to use Superier Drummer you need Studio One Professional or Studio One Artist with the 3rd party VST add-on. Check: https://www.presonus.com/products/studio-one/compare-versions
Install Studio One as 64bit version, install Superior Drummer 64bit. Open the Studio One preferences->folder->VST plugins and add the path to your 64bit plugins. You'll find Superior Drummer when opening the Studio One browser's instruments tab.