Supply sizing

Hey there.

Need some help from your collective brains. A friend with a master license in heating recommended this forum.

Mum-in-law has Parkinson's and Pop-in-law has cancer, so trying to build for all of us to caretake as things progress. All this on a shoestring, so bought an old excavator and old dump truck, rented a dozer and we'll see how far we get!

New build, coming off 6" municipal water supply at 80 PSI. Elevation change of 25' to house 500' from line. From there, there will be a garage with 2 apartments located another 200' away and another 15' elevation change including the second story. So we have the house, and then another building 200' away with a one level apartment for the in-laws (let's call that the apartment), and a small studio over the garage for my parents (let's call that the studio).

Total of 6 baths, 3 kitchens, 2 laundries, 4 hose bibbs for a total of 72 fixture units for the house, apartment, and studio.

The local town guys who maintain and operate the system had not heard of fixture units, so did not know how to compute pipe size for the supply. They did run it by some engineers briefly a few months ago, but at that time the house was 600' away with the apartment attached (had to move house site this week due to ledge/trees, and now the apartment and studio are in a separate building). Back this winter I found some chart on the internet I can't find again that showed me that with the pressure loss in line size vs. the amount of fixture units, that I was just (but definitely) into 2" size for the supply line from the municipal main. Now, we've moved the house 100' closer, and separated the buildings, so now it is 500' with 200' farther. The town guys and I are supposed to do a wet tap this Friday, and they are asking what size water meter I will be using in the near future (1" or 1 1/2" is supplied by the town, but they say that a 2" would be my cost). There will be one meter for both buildings.

Here's the three-part question: What size supply, water meter, and main inside the buildings is necessary?

Prices for corp, curb stops etc goes from $90 for 1" to $400 for 2" and everything else goes up too - blue poly, cost of wet tap, etc etc.

Wish I could find that little chart I used months ago when I first looked at this.
Here is a link to a somewhat helpful webpage:
http://www.greenbuildingadvisor.com/sites/default/files/JLC - Sizing Domestic Water Pipes.pdf

Do I still have to do a 2" supply? Or now that the distance to the house is reduced from 6 to 500' can I do 1 1/2"?
What size supply do I need to run to the apartment and studio (2 kitchens, 2 1/2 baths, 2 hose bibs, 2 washers)?

According to the link above, maybe 1 1/2" is enough for both and then run a 1" main inside?

Another possibility: Do 2" and reduce outside the house to 1 1/2" at a curb stop, enter the building and go through an. 1 1/2" meter, and then run 1" after the meter to the apartment/studio?

Don't want to over-engineer this, but also don't want to spend thousands unnecessarily. Especially not knowing how to account for demand, since everything won't be on at the same time (or do fixture units already account for that?).
Just scary that I was told that a 12 story building being built in a nearby city was being fed off a 2" line.....??

THANKS in advance for any of your help!