What you are wanting to do is part of the "Great Loop Tour". If you search that term you will find a bunch of webpages, organizations, and books
Here are a couple of links:
Cruising the Lower Mississippi River
Books and Maps about Cruising America's Great Loop - Raven Cove Publishing
But as I said there are quite a few others.
Personally, I have a ton of experience on the Mississippi
but it is all upriver from there so I can't help with anchorages
other than to say I think there is a 150+ mile stretch with no fuel
stops somewhere down there.
Also, here is a link to the entire navigational chart, all 87 MB/316 pages of it: