Does anyone know any tour operators (or other info) for some
singletrack action down in Panama City, Panama besides
extremepanama.com? They aren't running any tours later this month.

Well, I ended up getting tours set up with www.adventuresinpanama.com. I did the pipeline tour and the fort san lorenzo tour.
The pipeline tour was a tough ~20 kilometer ride. It was on barely maintained fireroad trail. Lots of uphill and downhill complete with various monkeys, anteaters, butterflies, orchids/plants.
The fort san lorenzo was an easy ~10 ride. It is on wide gravel road with an excellent view at the fort.