I think for 2 weeks in one country is enough time to see and do a lot in Panama.
You can relax, party, snorkel, surf, scuba dive, and fish in the Bocas del Toro islands.
You can hike Volcan Baru and the mountain forest, visit hot springs, horseback ride, white water raft, and zipline in Boquete.
You can visit colonial pirate ruins in Portobello or Colon
You can shop, go clubbing, and see the canal in Panama City
You can see paradise, some of the most amazing beaches, and indigenous people on the San Blas islands
The girls are really beautiful so if you're single...
And the buses are tricked out with bass speakers and flashing neon lights and I <3 RUM (or JESUS) signs