You should ask your water supplier, or pretend like you are getting a permit for your sprinkler system from the city and ask what they require. You may not have a choice. Even if your drip emitters are the same elevation as the sprinkler heads (PVB) You can raise the PVB 12 inches above the tallest drip emitter. If this is not a workable idea due to the piping and head placement then you may need an RP or DC depending on the local codes.
Good Luck.
You may want to add in to the budget the cost of a backflow certification once installed. This is to insure that it is working properly after installation. As a tester myself, I was surprised how many brand new installed units failed.