You sound a bit scattered at the moment, which is natural but not necessarily productive. We've all had a first time, and companies which ship bikes will help guide you through the process (some more agreeably than others) because that's how they make money. I'd suggest starting by exploring this site, including for example https://www.horizonsunlimited.com/ge...pping-the-bike and the links there.

You'll probably end up concluding that Raleigh isn't quite an airfreight transport hub, and neither is Ushuaia. That means you might end up shipping from Miami to Buenos Aires or on another similarly well-traveled path.

On the other hand, you might balk at airfreight prices, which are currently much higher than they used to be; even in December it's not that hard to drop south to the Gulf coast and scoot across into Mexico--I've done this, watching the weather for cold, frost, and winter storms. That would enable you to run your trip in reverse, more or less, although unless you move really quickly or have a lot of time for exploring you'd end up arriving in the southern Andes in wintertime, which is definitely less than ideal.

Airfreight across the Darien is quite simple, therefore not really worth worrying about just yet. At the moment, your focus should be on overall (seasonal) scheduling, finances, and where your trip is going to start. The rest will mostly fall into place based on those decisions.

Hope that's helpful.

Mark