I dont know of any sources of this specific information per se. My 2 cents on the topic, without knowing exactly what it is you wish to water: garden/turf/flower beds/etc..., would simply be that with the addition of a filter and whatever type /style emitters you choose to use all other aspects of your system could remain in place and unchanged. By this I mean your backflow, valves, mainline, controller should be suitable as you would simply be changing from overhead to subsurface water application.

This is a broadly generalized answer but what I envision as an example is a perennial bed in my yard, it is currently 1 zone on my system with 7 spray heads in a linear arrangement; I could easily add a filter and replace the first and last spray head with a riser feeding a labyrinth of drip tubing placed under the mulch and running throughout the bed, the other five heads could be removed and plugged at the saddle. Real quick, super easy, and as I envision it exactly what you wish to accomplish.

I am working on this very thing right now for some of my trees. Basically I have a peforated pipe (empty of course) buried in the ground with the bubbler fed directly into it with a cap at the top that opens only when upward pressure is placed on it by the water should it overflow but prohibiting dirt from entering at the top. I have tried the perforated pipe at HomeDepot or Lowes but have only had moderate success. I included a link for an illustration of the type of perforation that seems to be better suited for subsurface watering.

Here is a link that might be useful: Sample type of pipe.