I am looking to buy a new water heater to replace our existing one (an A.O. Smith model about 10 years old, with a first hour rating of 74 gallons). We have a 4-bedroom 3 bathroom house. While our current family of 5 are not exactly water hogs (e.g. we don't typically take very long showers), I also want to anticipate that if we sell the house, the size would be appropriate for a typical 5-person family with teenagers.

In doing some research and talking to local plumbing companies, it seems like I should target a heater with about 100 gallons or more for the first hour, so probably a 60+ gallon tank. The models I have been quoted are:

A.O.Smith GCVX50 total installed about $1200 - $1400
A.O.Smith FCG-75 total installed about $1700

Bradford White MI504S6 $1300
Bradford White MIXR65 $1500

It seems like the actual heaters run about $600-$800, so these guys are asking for about $800 in labor.

I would appreciate any help in understanding
(a) which models to go for - are there other models/companies I should be looking at?
(b) if these quoted prices are reasonable.

I live in the Chicago area, so I do expect that labor costs are going to be on the high side.

Thanks in advance!