If your going South of the Equator or just to Central America, try Copa. Try their web site for reasonabale prices. Also you earn OnePass Miles and can use miles to upgrade. Recently traved to Brazil through Panama from LAX for New Years Dec 26 to Jan4. They had many seats to purchase and I was able to upgrade to Business using miles. I think I purchased my seats in August or September for the December trip.
While they are differnt Companies they fly the same type of planes and share Presidents Clubs as well as One Pass.
In the USA Copa flies out of LAX or Miami. Sample flight from Miami to Rio through Panama was $441 each way. That was a Dec 25 to Jan 1 trip. Got to enjoy New Years In Rio. . its amazing!.
Also Copa's cancellation policy is pretty good.
www.copaair.com Good luck
P.S. Just checked Bogota, Columbia from Miami and its only $172 to $242 each way. I am sure you can have lots of fun there. Just do not take pictures. Plus you will not be on a plane for as long as going to Rio.