Our favorite is Mosquito Fleet. Typically we reserved one panga for three adults which is a tight squeeze. This year, my son, Joseph, tagged along. Even though he is only ten years old, we had a traffic jam during hookups. I recommend no more than two on a super panga.
Some fleets also have mini cruisers available.
These can handle the extra person. Mosquito Fleet also offers a full size cruiser that can handle up to 6 people. There are other very reputable fleets in La Paz, including Pirates, but we always prefer Lamberto as our skipper. He seems to get what we want and make a bad day good and a good day better. Now, to the fishing.