You could try "Historical Sketch And Roster Of The Kentucky Seventh Cavalry Regiment: Confederate (Kentucky Regimental History Series Book" available on Amazon. My experience with published regimental histories has been mixed, largely because of problems with the data on people who served in the regiment.
The following source lists several Cantells but none in the 7th Calvary CSA.
http://genealogytrails.com/ken/Ky_Confederate_Veterans.html