an anti-emetic like metoclopramide or domperidone is indeed highly recommended.
besides SN and an anti-emetic, every other drug is optional and won't help much. actually using less drugs may even be better, cause it reduces the chances of interactions.
metoclopramide is considered more effective to domperidone, but domperidone has less chances of unpleasant side-effects (Stan talks about this in more detail)
regardless of which one you choose, do a single dose a couple of days before the day of CTB to see if your body reacts badly to that anti-emetic.
also I forgot to mention about fasting: the amount of time depends of how "heavy" your last meal was. if you ate something that has a lot of fat and fiber and is hard to digest, or a very big meal, then I'd go for 12+ hours fast. if you ate something light, low in fat, low in fiber, easy to digest, then maybe you could even get away with a bit less than a 8 hours fast.
I wish you good luck regardless of what you choose.
you can change your mind if you feel like it and that's okay. we all change our minds. this is a big decision and, in my opinion, we probably only live once.