Yes, you can receive your goods purchased in the US and shipped to Panama. Personally, we use something like a Mail Boxes Etc., which provides me with my address in Miami. I get Amazon to deliver to my Miami address and then Mail Boxes Etc. puts stuff on a plane every day from Miami to Panama and the goods are distributed to all the locations in Panama.
American retailers could also ship directly to Panama but it is more expensive. If you’re going to order online, having a service like Mail Boxes Etc. (there are a lot of other versions of this service) is the cheaper way to go rather than having the retailers directly ship your order from the US to Panama. It is generally relatively inexpensive to use something like Mail Boxes Etc. but if you order something heavy like a generator then that can be relatively expensive. Mail Boxes Etc. ships your order to you and you pay for that shipping. If the duty people don’t figure it out (you’ll notice that Amazon will ship your order in a brown box), often times you will not pay a duty but sometimes, yes, you will pay a duty. However, I haven’t had that happen to me in four years.
(Via Espana, a street near a Mailbox Etc., Panama City, Panama, pictured.)