Here are the two sites that i worked off of while I was down there in June of this year - 2012.
The first link is analogous to Eros while the 2nd link is more like backpage. I called Lola Star from the disintas site, and she was not quite as good as advertised. I called a girl named Katalina from the mundo site, but I see she isn't advertising there anymore. She was great. Lots of kissing, dancing, sucking, cumming and bottoming for me. She might have returned to her native Colombia. The mobile # she used in Panama City was 66666809.
Expect to pay $100 or more. Since Panama uses the US $, they seem to charge a little more than others in Latin America. By the way, no upsell with katalina as opposed to the Lola chick who wanted to chg me more to see her cum.
Good luck, be safe, and have fun.
Here are some pics of Katalina...