Hi Madh,
This is a very good idea to spend some time in French guyana.
I use to go over there every year.
If you collect coleopters, the good season is from August to october.
If you visit my web site, you will find some good adress to sleep in the jungle.
http://www.cahurel-entomologie.com
I wish you a good trip
I will be there from 24 november to 14 december 2010.