Hi Bridget
It's likely to be warm (20-30 degrees Celsius) and very wet in the jungle so some good rainwear is essential. I've never owned a poncho so I don't know much about them but I would say it is worth splashing out (pardon the pun) on some reasonably good rainwear. It would be a shame if getting wet detracted from your experience.
I have forwarded your other questions to our agents in Peru and I will let you know when I hear back.
Kind regards,
Olly, your editor