I'm no expert, but from what I understand, using those meds you listed, even in high doses, will result in failure. That is probably why you are not finding anything definitive online.
An older version of the PPeH book explains how using over-the-counter sleeping pills as a sedative, like Temaze / Temazepam oxazepam / Serapax Nitrazepam / Mogadon all from the benzodiazepine family of drugs/sleeping pills, are NOT lethal in and of themselves, even in overdose. But crushing up 25-30 tablets of these pills in water would be a reliable and peaceful way to go when using an Exit Bag as the pills will sedate and immobilize the taker enough so that the body's Hypercapnic Alarm Response won't activate (which would cause one to remove the bag otherwise) when the CO2 levels rise inside the bag and in the bloodstream.
That older version of the PPeH book details the story of an older Australian man who successfully did himself in using those sleeping pills mentioned above, a shot of whiskey to wash away the bitter taste (and to potentiate the sleeping pills), and an exit bag that he made himself with an elastic opening that would fit around his neck. He waited for the sleeping pills to take effect (about 15 minutes, while comfortably seated and reclined in a lay-z-boy type of chair) by using his thumbs to hold the elastic of his exit bag open under his chin so he could breathe, with his elbows on the armrests, then as he began to fall asleep, his arms would fall down, allowing the elastic at the opening of the bag to gently fit around his neck and within about 1 or 2 hours, he was peacefully gone, effectively dying in his sleep. The exit bag is the key thing. A person can live without food for a month. Without water for about a week. Without air for only 5 minutes. So whatever drugs you choose to use, be sure that they will really put you into a deep sleep, or possible coma, and use a homemade exit bag.
This is how I plan to go one of these nights using a plastic bag and an alcoholic beverage when I am ready. But in my case, I have actual powdered N at my disposal that I was able to get several years ago from China before that avenue was closed. The N will put me to a deep sleep within 3 minutes, into a coma shortly after that, and a large 96-gallon bag that I have prepared in advance, that I can quickly secure over my head before the N takes effect and that will painlessly me leave me in a hypoxic (lack of oxygen) state without me realizing it within 1 to 2 hours, not 12 to 20 hours if using N all by itself, thereby greatly reducing the chance of possible discovery and unwanted rescue. Not unlike what the 39 Heaven's Gate cult members did in 1997. If you are unfamiliar, Google them.
