I'm a homeowner with an irrigation system already installed. The system has 64 RainBird head, a Hunter SRC controller. I live on just under 2 acres. The problem I'm having is that I have one or two RainBird heads that go bad every year and constanly need adjustments. Is there a better head that I could start replacing these with when they go bad that would be more maintenance free? Second question, what are essential tools for working on this system that will make my life easier when replacing these heads and working on the system? Also, is replacing the heads the best thing I can do to upgrade the current system? Should I do something else that would make the system more maintenance free? BTW: All of my heads are rotators. Thanks for all your help for this new guy.