I want to have a picture of my family close by. If I choose to CTB, they all will have died. I'd like them to be my last thoughts here.
I'd likely go via SN, so a few other items I think I would go for are: a couple of hot water bottles. I think that would be comforting. I also bought a small canister of oxygen. The whole breathlessness thing scares me but, I don't know if it would help much. I'd also obviously prepare the area- put up notes on the door, set up delayed emails, put down plastic sheeting. Get a bucket ready.