Thanks everyone for their input. I'll try to respond to the questions
and points.

First off, I calculate the cost of operating a 17KW unit at 50% load on
NG at about $10/d (the cost of NG here, in Calgary, Canada, is about
$3.50 per GJ (gigajoule)). IIRC a GJ is roughly the same as 1,000,000 BTU.

I'm in Canada so no worries about Obama. We also don't get earthquakes
here so no worries about interruption of the NG service (we have places
around here that have not had in interruption in several decades).

This unit is not for a home but for a wildlife rescue/rehab facility
which is not attended 24 hrs/day. So, we want auto start/stop. It has
to be idiot proof as some (most?)of the staff & volunteers are what you
might call mechanically challenged.

In short, it has to be reliable, work automatically and, not break the
bank as we are a non-profit with limited resources. I have had some
comments from a couple of suppliers here that Generac warranty and
service are kind of spotty here but have had no adverse comments on any
build quality/reliability issues.

Thanks again for everyone's input.

Laurie (not female BTW) Forbes