I've got a Tony's PS-REV, the predecessor to Tony's current reversing unit. My reversing section includes my yard, and all of this works just fine. As a bonus, this reverser also includes a circuit breaker, so if you're "fiddling" cars on staging and happen to short out the track, the rest of the layout won't be affected.
This auto-reverser has a 2-amp capacity. That's plenty for me. You might want to check on those illuminated passenger cars, though. If you have multiple incandescent bulbs, you could be drawing close to an amp just for that train, before you even add an engine. You might consider adding a cutoff switch to kill power to the sidings individually, so you can turn off the lighted cars when not in use.
For sound engines, there are two things to think about. First, they draw more power than regular engines, and they draw power even if they are idling with sound. So, regardless of where they are on your layout, think about their power draw. Also, a sound engine will "recycle" its sound after a power interruption. With a solid-state reverser like Tony makes, the power interruption during a polarity flip is short enough that the engines don't notice it. However, some older relay-based units may cause the engines to reset on a flip. Stick with solid state to avoid this.