You should figure out how much demand you will have on the system, and size the pipe accordingly. It is hard to tell what the pressure losses will be without knowing the flow and inside diameter of the pipe.
The difference in cost between 3/4" and 1" pipe should not be great. I would use 160 or 200 psi polyethylene with no joints except brass or stainless adapters at the ends.
If you have a municipal sewer system, you should find out if they charge based on water usage. In my town you can put in a separate meter for outdoor use that is not also charged for sewer usage. They usually require a back flow preventer for outdoor connections.
With a supply of 95 psi you will probably need a pressure reducing valve. You should make sure it is large enough. You will also need an expansion tank to prevent overpressurizing from the water heater.