You've already got +59 STR on that WS set.
Don't really think you "need" to improve anything.
Snow and Light Gorgets, Askar Gambieras, Heroic Boots+1, Gnadbhod's Helm, Maat's Cap, Strigoi Ring, Nocturnus Mail, Hachiryu Haidate are all pieces where you could add a little more STR, if you really want to.