New water line
Pex is allowed and it easy to install.
Don't let any of it be exposed to sunlight for more than 30 days total and don't have any connections underground. If you do have connections then use sharkbite connections which are approved for burial.
No need to use any conduit.
You will have to use at least 3/4" and those are big rolls. I just take the roll, connect it to the source, roll it out in the trench and then cut it off at the end. Make sure you leave more than you need to get to the shut off in the house so that you don't have to be doing a lot of splicing. Every splice will decrease the flow and 90's are the worst.
My idea of a perfect day: No where to go and all day to get there.