combi and car rental

Is it possible to take a combi to Troncones? or to the mayan ruins near Penas I think that's the location? or is it best to rent a car, if so from where? airport the best deals? any companies to avoid?
some places to consider driving to if we rent a car for a few days. We're thinking Acapulco worth it?

Also, looking for cheap bike wheel tubes (26 inch wheels) as we've been doing some mountain biking and the thorns just love us to bits. So too the mosquitos at night as we are staying close to the forest reserve.

Any place to rent small sailboats (14ft or so)? I noticed club med has them but they want 1300mx per person which includes access to all their stuff plus a meal. But, they seem pretty booked up most days.