I would suggest you either cut and past or click on this link to find an appropriate serviceperson. handyman.contractornexus.com/Water-Heater.htm
American Water Heaters.
American Water Heaters
A domestic plumber fits and repairs faucets, toilets, sinks, water heaters ,broken pipes, water filters etc.
American Water Heater
RHEEM manufacturing. USA
GE
One of the best electric hot water heaters on the market is Reliance Lowboy and Reliance 80 gal. The are sold at Ace Hardware. There is a web site that rates hot water heaters and that is Heater.Housekool.com They list all the top rated electric and gas hot water heaters.
I doubt the gas company will install a water heater. Too much liability.
The manufacturing company that makes AO Smith water heaters is simply named A. O. Smith Corporation. They are one of the leading residential water heater companies in the US.
The company Noritz is a heater company. They specialize in making innovative solutions for hot water heating, such as their tankless gas water heaters.
Yes, Home Depot sells Rheem tankless water heaters. However, the Rheem company website also offers them and the company may have a better price. I would also look on Amazon.
What type of water heaters have good recommendations? I wouldn't really care for water heating unless my water isn't cold. But the best two I recommend would be Rheem Water Heater, and Utah Water Heater Company.