Submersible well / Pressure question

Jack is pretty close to right Roger. Vertical rise is your enemy. You're pumping fine now with the rise out of your well so as long as you travel in a horizontal manner with the remainder of the new line you will be fine. No need to exceed the size of the existing line coming from the bottom of the well. If your coming out of the well with a 1" line then the only benefit for increasing the line size would be for holding ability, or reserve. Your 40 gallon tank will be more than sufficient. Maintain existing line size unless it's small then you might elect to pull the pump and increase the size. Make sure the line size is as large as the orifice coming out of the pump. Hopefully it hasn't been necked down. Neck it down when you go into the house from 1" to 3/4" then neck down again at the service valves under the sinks and lavs. You should have no issues with pressure. Do your lawn system in zones.
Small Block