Hello Caroline,
Chilean customs is quite straightforward, as long as all the paperwork is filled out correctly, they’re sticklers for details. Make sure you’ve got all your cases correctly listed on the carnet, and don’t put anything disposable on there, you’ll need everything on it again on the way out of the country.
The local equipment rental houses are fairly good, and have just gotten much better with the addition of Congo Films to the market. It’s certainly worth quoting the gear you need locally before deciding to bring it all with you.
cheers, Bud Theisen