Fast Water Heater Company

Called the company Monday. The plumber came next morning, ready to install.
The estimate was pretty close to what I expected from the phone conversation, the only additional cost was $69 for connecting water and gas pipes with ground wire.
Leka (that's installer's name) had patiently answered all my questions, filled the permit application, installed the gas water heater very quickly and the building inspector has approved it next morning. All in all - a perfect job.
My advice to homeowners is to print the building permit application, have the plumber fill it out, then while he's installing, go to the building dept and pay the permit fee. This will save you some cash (contractor relies on a 3rd party for this paperwork, so there is an extra cost in it for you).

Total project cost with this company might be a bit above average, but in my opinion, it's worth it, as these guys will do a professional job.