Mark,

Sounds like a great trip. I have done several trips around central America, as well as from Argentina to Alaska, and there is a LOT to see. Hope to see you here in Panama. A couple of pieces of advice:

First, don't count on camping. It is not popular or well organized in central America, and camping in the wild can be dangerous. However, you can find many inexpensive hostels and hotels along the way.

Many of these places are small. A group of 10 would be a definite challenge. I agree with those who suggest a maximum of 3 or 4.

Don't count on too many miles a day. First, because you came to "smell the coffee". Second, because the border crossings in central America are a real PITA. These are the people who invented red tape. Sometimes you might get through a crossing in an hour, but I've also had it take 6! Bring many copies of your passport and title documents... it will save you time.

Also, if you speak Spanish you don't need the "tramitadores" at the borders, but if you can negotiate a low price (like $10) they can be worth it (just to keep the others away).

Some places I really like along your route:
Riodulce, Guatemala (with a day outing to the hot-water waterfall at Paraiso)
Samuc Champey, Guatemala (a magical place)
Antigua, Guatemala
Granada, Nicaragua
Tulum, Mexico (go diving in the cenotes)
Chiapas, especially around San Cristobal de las Casas, Mexico

send me a PM and I'll try to think of some more (I'm having a senior moment)

and of course, give me a call to have a in Panama if you make it here.

__________________
Steve Barnett
Panama City, Panama