I primarily use instant, push-in connectors and 1/4" tubing for the majority of my props.
For speed control on smaller air cylinders, the standard speed control needles work fine, but on larger cylinders, certain ones can be too restrictive and not dump enough. You can use these at the air cylinder or at the exhaust port of the air valve. If mounted at the air cylinder, then you can add an air silencer at the exhaust port of the air valve. For our usage, will want the "meter out" ones. Meter-in seems to less common, but some suppliers have both versions.