Zofran should be fine. Just make sure you take enough as far as a stat dose and a 48 hour regimen if you want to play it safe. Here's a thread about it: https://sanctioned-suicide.net/threads/anti-emetics-reglan-vs-zofran.14609/#post-286593
It also helps if you have benzos so you don't have to suffer through whatever symptoms you might experience and not be awake when you eventually go into cardiac arrest. I'm not sure how Abilify will affect the Amitriptyline. You might experience Serotonin Syndrome, which wouldn't make for a peaceful death unless you take a benzo like Diazepam.