Which books has the guard shotos information? It is the type of lightsaber that the main character if the force unleashed video game.

Nope he used plain ordinary light saber hilts. He used Reverse grip Shien as his primary fighting style.

Guard Shoto are the Lightsaber Tonfa.

Guard shoto are in Keeping the Peace. Reverse grip attachment is in Endless Vigil.

Compare:

Tonfas

to regular hilts

However the Shien Reverse Grip is in Endless Vigil. So either way you are covered.