I don't really know much about the tour because is new I know is on Guaynabo here is the link:
but as I see it Puerto Rico has a lot to offer but if you are waiting to see big trees I don't think they will be that. If I can recommend a tour on the "wild side" of the island how about
"El yunque" rainforest
Also there is a buggie tour that can be fun and exciting without the risks of breaking a leg or something
you can search for
ATV adventure in the rainforest Puerto Rico on the net, for all I know is more interesting and I know your kids will love it...