The beginning of your problem is that this is not, in fact, needless to say, because what you want to do is effectively impossible without going down that criminal path.
Consider for a moment what you are proposing. For a start, it would entail a significant uptick in demand in Western zoos for wild-caught individuals - a course reversal of the last 70-odd years of developments in Western zoo culture and ethics.
Then, not only does the world need to change to fit in with your dreams, but you somehow need to be the guy they go to? Sure, it worked for Durrell, but as you say he was collecting in the days before CITES and domestic wildlife trafficking regulations, not to mention that most of his trips were to European-controlled colonies, not independent states. You would need to comply not only with the legal obligations of importing countries, but those of the post-colonial states you want to work in. Governments that have every reason to favour their own citizens for such projects.
And 'projects' is the word, because we are not going to go back to postage stamp collecting, where an animal dies and you order up another one from the Congo. Where zoos still countenance wild-caught specimens it's invariably to establish those species in captivity as an insurance population. That implies a collection that is limited in scope and time, and almost certainly will rely on local knowledge and skills - not a random Coloradan with a net and an Indiana Jones hat.
Your fantasy is not real, and it is not real for reasons the bulk of people in this community think are very good ones. I'm sorry, but that's it. If you do just want to go to the Everglades and catch Burmese pythons, good on you, have at it, and I hope it's a fulfilling and lucrative job for you. But you won't be placing them in zoos. That's the reality of the situation.