I was able to learn a lot about your water usage. It sounds like you are concerned about your drinking water primarily, which will cut the cost down. Since your faucets will be spread out, I think it would be the cheapest and easiest to have residential-style
filters at each location.
Here are two systems that have outstanding filtration:
http://www.waterfilters.net/Culligan-US-EZ-4-Under-Sink-Filter-System_p_0-43
4.html
This one is very easy to change. You just twist and turn to remove and
install filters.
http://www.waterfilters.net/culligan/undersink/housings/SY-2650.htm
This one is one of the most popular filter systems around. It is frequently
in consumer reports. It has similar filtration as above but it has two
stages of filtration.
If you want reverse osmosis water (this is probably the same as what you
were getting from the bottled water people), then it will cost a little
more. Reverse osmosis systems have lower flow rates generally and require
tanks.
Here is a very good reverse osmosis system that has filters that are easy to
change:
http://www.waterfilters.net/Good-Water-Warehouse/Reverse-Osmosis/systems/PuR
OTwist-4000.htm
Here is the latest and greatest reverse osmosis system:
http://www.waterfilters.net/GE-Merlin-Tankless-Reverse-Osmosis-System_p_0-14
67.html
This one has a higher flow rate so it doesn't need a tank.
A handyman can install any of these systems very easily. No plumber would
be needed. They all come with faucets that would be installed on a sink.
Again, a handyman could easily take care of this.
I'm not sure what your budget is, but these systems would pay for themselves
very quickly. They do require replacement filters, but the cost to use them
is MUCH MUCH less than the cost of bottled water. Info on the replacement
systems is on each of the above links.
The four links are organized from most affordable to highest quality. All
of them are very high quality though. I did not include any of the cheap
ones. It sounded like you might need about 11 systems based on where people
will be drinking water.
Thank you,
WaterFilters.NET