Almost certainly you will need to have a seperate hand wash facility, this doesn't necessarily mean a plumbed in sink as you can buy portable ones. as for cleaning you milk jugs I would recommend using a pitcher rinser instead of a sink, they are a life saver and can double as a waste sink for disposing of your excess milk.
As for grinder options then this will depend on how serious you are taking it and how consistent you wish to be, a manual grinder is great for very high demand as you can pre fill the doser by grinding lots of coffee. However it is harder to be consistent in your shot size, meaning that if you are serious about providing top quality coffee you will need to weigh every shot, which this is ideal it is not practical if you are busy. Also coffee is only really at its best for around 15 minutes after being ground after that it starts to degrade. this is a pet hate of mine that I see in a lot of shops where the ground coffee just sits there hardly used and the doser is full.
Another option would be to get an on demand grinder, this will grind your coffee to an exact measure for every shot, keeping you consistent and cutting back on your coffee wastage, also as the coffee is ground individually for each shot then there is not degrading of the coffee.
If you still need help then drop me a message, I am new to the forum but have experience with owning my own coffee shops and can not only offer advice but source equipment and great coffee.
Not sure how an on demand grinder will affect your power usage though, as staring the motor tends to use more power than continually grinding so you may need to factor the peak power into your calculations as it would be start-stop a lot more than a traditional doser type grinder.