Due to a revolver's design and the Sp's size,, you will not get away w/o some flash,, nor the noise. Especially indoors & if it were dark.
Here's a few thoughts; Get a good quality flashlight to accompany the firearm. That way,, you can both blind an attacker, (hopefully) and more importantly identify your target before you fire. Total darkness will cause momentary flash blindness,,, but are you SURE of your target? Another thought is to train to be able to shoot while holding your firearm along your side,, slightly in front of you,, using both hands, so as to NOT place your off hand in front of the muzzle. Plus,, if the firearm is close to you,, and not stuck out in front of you,, there is a lesser chance of an attacker grabbing it & taking it away from you. If you choose to use the "low firing SD stance," one handed,, you can keep your flashlight up alongside your head to keep your hand away from the muzzle,, and control where your light is going.
In short,, you are not going to find ammo that would do the things you request,, AND be an effective man stopper. It is better to train for SD tactics to make the outcome of an assault in your favor.