I'm going with SN cause it seems easier to pull off. I'm terrible when it comes to assembling things and not mechanically inclined in anyway. Exit bag sounds peaceful when done right though.
The exit bag from the PPeH is not very difficult to obtain and put together, at least in the US. All that is required is a small cylinder of inert gas, a flowmeter regulator for the specific gas, possibly an adapter for the output for connecting plastic tubing, the plastic tubing, and the bag with elastic cord inside a "hem" at the opening. It does take some research to understand what items to buy and where to purchase them, but it is not that difficult, even for people that don't have any technical knowledge or ability, as long as one is willing to ask questions. I feel that the discussion on this forum about using other ways to deliver the gas such as masks, etc. makes this method sound much more difficult than it is. Using the simple, proven bag is much more preferable to any kind of mask that I have no information about how effective it is. Also, the Mad Dog Brewing regulator has confused people into thinking they need this 'click' style regulator, when a flowmeter regulator from a welding supplier is much easier and cheaper to obtain for any inert gas, not just nitrogen.
I don't know any more information about SN other than what I have read on this site, but for me, there are several issues. I would have a lot of difficulty in obtaining the recommended antiemetic, and may vomit anyway. It doesn't sound peaceful and painless due to the nausea reported and other signs of distress that have been described.
When I read here about those who choose potentially painful, violent, frightening, risky, and otherwise difficult or illegal methods, I want to tell them to consider the exit bag, the only method I know of that is truly peaceful, painless, completely legal, and poses no risk to others, but advising someone directly on how to carry out the act isn't allowed here.