You have to be wary of heavy carry ons when flying European carriers. Many have 8kg limits and will either charge extra (or more likely in my experience) try to make you check it. Sometimes, heavy but small bags will pass initial scrutiny at check in. Still, It's unlikely that a Pelican Air would be allowed for carry on. I've used Lowe Pro and F-stop bags successfully in the past and at least with the F-stop bags you can remove the ICU.
Hudson, one can still use third party reservations as long as you get the actual airline flight confirmation number and connect your contact info as soon as you book with the airlines as you mention. It's also a good idea to get confirmation of your actual seat location to avoid bulkheads as some travel companies don't have enough info on actual seat locations. Something also to take note with overheads similar the Embraer craft (170-175) you flew on, some airlines such as Latam Airlines will not allow carry on luggage over 22 pounds above the seats on their larger Airbus A320s and will walk through the wait lines and actually weigh bags. I have encountered this issue on several trips from Lima to Cusco to shoot Machu Picchu.....strong chance you will be checking unless you can accommodate under seat. Given the current political turmoil occurring here (or in Chile), checking baggage with expensive equipment is not an option (anything of value will be taken...even food). Shimoda Explore 25 is a great option for under seat travel on CRJs, Embraers, and larger Boeing and Airbus. I have always been an advocate on less is more when packing for any kind of air travel in US or international. If possible in the US, try to not check any bags when traveling on multi-link unless you can afford to not have your luggage the same day.
