Thought I’d come back and give this question another try.
http://www.gapadventures.com/trips/exploring-the-amazon-rainforest/SEL4D/2011/ is GAP Adventures’ sole Amazon tour IN Ecuador if you just search tours less than 7 days. 4 days in duration, it takes you from Quito to Coca and their jungle lodge, and back. Includes motorized canoe, caiman hunting by flashlight (you look for the eyes ;)) and a naturalist guide to tell you about the environment and animals around.
Unfortunately this site is only in German, but maybe you understand some basic information, because there are also lot of pictures in it:
http://www.hauser-exkursionen.de/amerika/eck12von_den_anden_zum_amazonas.php
It is a 18 day tour in Ecuador that leads from the Andes until Amazon. I know you have only time for 4-7, but maybe you can get some suggestions from it.
Here is another German site which offers a lot of different tours in Ecuador that are not necessarily Trekking tours like Hauser:
Credit:stackoverflow.com‘
4 Mar, 2024
4 Mar, 2024
4 Mar, 2024