3CX 1989 Hammer circuit

Hello. I have a question about how to add hammer circuit on my 1989 3cx. For the pipes along the arm there is no problem. The only problem is the valves. Someone is advised to install a priority valve with electrical control, others say they install a system more similar to the original (diverter and valve in sequence). What do you recommend me?

3CX 1989 Hammer circuit