Docdan,
There is only ONE outfit I would go with and that's
www.Amazontours.com They are the oldest operating outfit on the Rio Negro, largest tributary off the Amazon. The area that they have access to has given up not only the world record pea**** bass but several line class records as well.
Without a doubt the best time of the year to go is November. Season has just opened up, water levels are usually down and not only do you catch numbers but you catch big fish as well.
If you decide to go pm me and I can get you more details. I'm already booked to go back this next November.