Hi Mima
I booked the Amazon add on as I have found on most of these trips the majority do but mainly because its an area that interests me. It looks really good and the chance to see the rainforest and Amazon for real. The office will no doubt tell you how many have booked which may sway your decision one way or another. I know when I went to China 4 people didn't book the Yangtse cruise add on and then tried to but were unable
I was flying Heathrow but found I could go From Manston via Amsterdam which suits me much better.
I hope you book so please post on here if you do
Keith