Need help finding a car battery charger/starter.

I’ve heard Schumacher is good so if not let me know. I want a car battery charger that can charge it (of course) but also start the car when a little under voltaged. I also want the charger to be automatic so I don’t have to monitor it. Why am I having trouble find a unit that does all 3?

Oh and one other thing. I’d like a gauge that reads the voltage. Sure I can do it with my multimeter (which my son has lost apparently) but I just don’t want red light/green light