Have you checked out the proseptive (brand names, RainBird, Toro, Orbit, Hunter, you know www.
bla bla bla.com) web sites.
Myself, I never have had a call to use multi streams before, but I can tell you that they don't work very well in high wind sites. That's why I do not see to many installs like that on commercial sites in my area. They were the way to go before, but as you said, to many problems.
Do you have either Ewing,Horizon,or GreenMark in your area. At least the shops in my area have always been able to suggest,and if not, point me in the right directions.