Drip irrigation parts?

I'm looking for some info on drip irrigation parts. I'll be setting up a
continuous water change system down the road (tank needs moved first), so
I'm doing a bit of research. I've seen that some people use a pressure
regulator valve and others use a "drip irrigation controller". I gather the
drip irrigation controller is more precise and more expensive. Perhaps
someone can give me the details of their setup and the pros and cons of the
two methods. Also where to buy parts, HD for a water pressure valve?

My plan is two use a water pressure regulator, water filter with GAC
cartridges, siphon overflow and a solenoid with float switch for backup.
BTW, should the pressure regulator go before or after the water filter? I
may also have to add an auto doser for dechlor, but I'll have to do some
testing first.

TIA