In the suicide wiki it says it's okay even if you have GERD. As long as you are able to keep it in. It will work. And vomiting doesn't mean failure anyways.
If you aren't under any medication I suggest getting it. I don't have GERD but I have acid reflux sometimes when i eat too much food. I take antacids that time.
For the SN. I have got metoclopramide, ondanestron, Omeprazole. Each Target a different thingy in our brain/ body. I suggest the same for you. It's recommended in the PPH book generally. You can get other alternatives if you don't get the exact drugs, it's what I could get here.
I've been prescribed esomeprazole for GERD, but the PPIs and the antacid are only meant to lower acid in the stomach. My main concern comes from the esophageal sphincter being loose and the volume of water I'll be taking with the SN and the benzos. If the volume of water exceeds a certain limit, the solution may get out of the esophageal sphincter into the esophagus and cause reflux and possibly nausea.
Right now I don't think I can take more than 100 ml of water at a go. More than that will certainly cause nausea or reflux I feel. For every 100 ml of water I take I have to wait at least 8 mins to take at which point I can take a maximum of 50 ml.
8 mins with the SN solution inside and it may be too late for the benzos. I can't risk taking the benzos beforehand as I want to be there in case I vomit for the second cup. I think water management will be crucial in such a case.
I hope the SN can be prepared in 50 ml and the benzos in maybe 25 to 50 ml.
I was planning to go with meto but I am losing weight rapidly as I can't eat much to keep the acid down away from my throat. I thought if the weight gets too low and if I have to ctb as I was, then domperidone was the safer option as I've seen reports of meto causing mild EPS in the case of a person who was underweight at 48 kgs..
But meto would be my first choice given that I have GERD. Maybe I should just take the meto and plough through whatever happens. I also plan to keep 4 drinks of SN prepared kept in standby in case I vomit.