Electrical

I'm looking to add 2 outlets under the bathroom sinks for a instant water heater. For master bathroom, your have access through the closet. The guest bathroom is more difficult. I'd like to add a light switch to the livingroom that would also be connected to an outlet as a 3 way switch. The outlet is on same wall as the new switch, but the other switch is in opposite corner. I'm wanting to change a light switch to a 3 way switch for the lights under the cabinets. The switch is for the garbage disposal. The switch that currently controls the lights is at the entrance to the kitchen with a refrigerator in the way.  Then add a push button switch for garbage disposal on the kitchen sink.  There is a hole where the dish washer's water empties into the sink. I'd prefer the dish washer empty directly into garbage disposal/drain. So, I'll send a separate ticket for plumbing work. I'm not sure which instant water heaters i should buy, so advice on that. I'd prefer to get a quote.