Have him tow the trailer! You can ride nice and light!
What is your budget? It will make a big difference in the gear you take. My bike was just over $2500 but all the other stuff has added up to more than that. You could go cheaper but then the weight adds up even faster. I've heard this ride described as the most expensive free bike ride in the world.
For shoes I am using Pearl Izumi Alp-X's. I am not sure which model but they seem fine. Fairly stiff but walking is great. I can just slightly feel the pedals while standing.
Just keep reading and you can learn a lot.