I am redesigning my back and side yard to reduce the amount of lawn. Yesterday I measured my water pressure and flow out of one of my valves from an existing zone, here is what I found:

Water Pressure is 70 PSI

Water flow is 21 gallons per minute

I am thinking of creating 3 zones, all using spray heads. Below are some pictures of these three zones:

The flags indicate where I think the sprinkler heads should go. They are colored by zone, white, green and blue. The heads are spaced around 9.5 feet apart.

The white zone has 14 heads, the green zone has 15 heads and the blue zone has 19 heads. You will notice the orange paint on the grass, that is where the new borders will be. A week from tomorrow I have a curbing company coming in to pour curbing. If you can't see the paint you may notice the grass is cut longer in the sections that will be flower beds, the exception being that huge clump of grass in the back yard that is just long because there is a pile of dirt there I need to level out.

A future plan is that the green zone will have a gazebo in the middle which is why I chose to use spray instead of rotors for this zone. When this happens I will just move the sprinkler heads and switch to 180 nozzles for the 4 heads in the center where the gazebo will be.

The system will use Rain Bird 1800 series heads with U8 series nozzles for most of the heads but I may use some of the VAN series for the smaller areas. The spec sheet can be found here:

http://www.rainbird.com/documents/turf/chart_USeries.pdf

http://www.rainbird.com/documents/turf/chart_VAN.pdf

So I have a few questions:

1. The nozzles have a 8 foot radius at 30 PSI, I am assuming at my higher pressure it will be greater or equal to my 9.5 foot spacing?
2. The Rain Bird 1800 series have a PRS version that has a built in regulator to 45 PSI, will this be worth the extra cost? Thinking it might so I get a more consistent spray.
3. Does my current design based on the pictures look like I will get plenty of coverage?

Any help is appreciated, I want to start trenching early next week.