Gonna suggest to complete and finish what you've started or else, you will end up hanging with 2 different sets of ninjas without completing either of them .. You already have 40+ frags so why not complete him since Shisui is a great ninja, there's no bad idea in completing him .. He's useful ..

With Edo Hiruzen, you're gonna need to have his son Edo Asuma to be able to use him smoothly .. Edo Hiruzen without proper buff and team mates is nothing but a power-lacking ninja ..