If you want an antipsychotic that is weight neutral your choices are pretty much Latuda, abilify and Geodon. Abilify really doesn't make you sleepy at all so if you actually want a sleep med that's not going to help you but it sounds more like you want stability over sleep and normal sleep can come with stability anyway. I don't think any of those three are particularly sedative but things can vary a lot from person to person.