What he said. If you ever need to cross rent amp racks, power distro, extension cables all that will matter is that you have what is available from vendors nearby. Also consider what non-audio vendors keep on hand. Lighting and generator vendors are good sources for cable. In my area California plugs are stocked by Sunbelt the construction equipment and generator rental vendor but no one else. The 800 lb gorilla audio vendor uses pin and sleeve for amp rack power, many of the mid sized operations use L14-30. Pick your best option for your work flow but in the long run making sure it's compatible with the likely competition will pay off.
Look at what you have around you and go with that. ...
