I would prefer jumping as a method to SN even if it were available, mostly because of how quickly jumping kills you. If you jump from a height of 100 meters, you will fall for less than 5 seconds and hit the ground at 159 kph (99 mph), and lose consciousness on impact. If you can get over the initial SI before jumping, this method isn't difficult. I would recommend scouting out you spot first, so that when you actually jump, you know exactly what you're doing and can be drunk or high without risking failure.
As for the height of the jump, I would recommend no less than 30 meters onto a solid surface. 90% of people who fall from 7 stories high (25 meters) die. However, and I cannot stress this enough, if you have access to a location higher than this you should absolutey jump from that location. I would even recommend travelling internationally if you can afford to, as it will permit you to jump from as high as 200 meters, depending on where you live and on your financial situation of course. There is really no reason not to spend a bit of money on going abraod to ctb if it decreases your chance of survival and the time it will take for you to die. I would also recommend jumping at a secluded location, like a cliff. The advantage of doing this is that your body will have more time to decompose while the authorities in your are investigating your disappearance. This will make it more difficult to identify your body when it is eventually found. This will be important to you if you want to your death to be recorded as an accident or to hide your suicide from your relatives. The odds are against you in this regard, but there is still a chance. In my country, there are bodies that have gone unidentified for 10 years, so there a still a shot.
This is really all you need to know about this method. I wish you the best of luck if you choose to ctb this way.
