What are all the parts I'll need to put in an a/c into a honda civic dx 2000? (Manufactured without)

I would look into an under dash AC add-on kit. They make for newer cars as well and not just the older classic cars. This way you don't have to rip apart your dash and attempt to alter heater controls. The universal under-dash kits run about $500, and believe me that is cheaper than trying to recreate the factory AC system and a whole lot less aggravating. If you insist on going the factory route, then hit up salvage yards for all the parts, but it may take a while as AC parts tend to get stripped pretty quick, so you might not find all the parts on a single car, and buying evap and condenser coils used is always dicey.

Find a donor car in a junk yard that has AC.

Owner would be better off selling the car and buying one with AC.