Cooked choux pastry can last for quite a while in an airtight container at room temperature, provided they have dried out thoroughly ie no damp dough. Can't remember how long I have kept them for (been years since I made choux pastry) but it was more than a few days.
Once filled, it will depend on the filling as to how long they keep. The filling will make them soggy so presentation wise they won't look any good and the soggy pastry will go mouldy at some point, but the filling itself will probably go off before that happens. Wouldn't personally want to have them more than a day or two at most after filling them.