Residential Water Line 1200'

I need to install a 1200' service line from the meter for a new home that we are building. Not much, if any, change in elevation in that distance. I have several questions and would appreciate any advice. Thanks!
1) Size and type of pipe? I have installed plenty of PEX inside homes but have never done a service line. 3/4", 1", or larger to reduce friction loss? Obviously don't want to spend more for larger pipe for little or no benefit. I don't anticipate rocky soil, but would the cost for smooth gravel, sand, or sleeving be worthwhile to protect the pipe underground?
2) Utility has offered a 5/8" meter. Is there any benefit to requesting a 1" meter? I think that would only help with volume, not pressure?
3) Should I install disconnects every few hundred feet to help locate and repair any future leaks?

 

http://www.engineeringtoolbox.com/pressure-loss-plastic-pipes-d_404.html

I'm not a well driller, just an engineer. That's a long run 1/5 of a mile. No reason to guess - get a pro to size this.

 

Friction is your enemy here...larger is better.

 

I think Oli Creek makes 2" in 1000' rolls, yep it's gonna be a pain to work with. I would someone who does geo thermal work to fuse on transitions that go from the poly to pipe thread, especially in the trench.