Hi. Yes 13 wires it the minimum to run 12 valves. But you may want to take into consideration the possibility that in the future one of the wires might go bad for whatever reason. One time I ran a 10 strand wire and after I was done it turned out one of the wires was bad. There are so many factors to consider. I don't know how far you're running the wires but I would run extra wires just in case. For example. Three sets of 5 strand wire.
As far as the valves go. We need more information. How much water pressure do you have? How much money are you willing to spend? Are you installilng your valves above ground or below? Ect. I know the "ss" in 5004 PLPC SS stands for stainless steel so I'm betting you want something better than average. You're going to get a variety of answers on this question. I like brass valves myself for a variety of reasons. They're easy to repair and the body doesn't crack or split open. I like Superior. Inline or anti-syphon.
If I can't fix it, it's broken!
