Watering System

I wish to instal a spray watering system beneath a pergola which covers the patio. All the spray systems I have researched seem to be for border beds where the spray nozzle is installed on a spike and plastic micro tubing. A more robust setup on the pergola would be standard 15mm copper tube and fittings but spray outlets seem to be the problem. any ideas from gardening plumbers out there?

 

Thanks WOO, drilling holes will not give me adjustment and will need to be graduated, a little time and cost consuming during experimentation. Shower heads? and roses a little impractical I would have thought and probably presenting the same water flow problems as drilling. I have considered reducing the pipe size at outlet and squashing the tube but still no adjustment and all experimental. Hate to spend time and money when afterwards someone will say - Ah! but you could have used ***** instead.