Marathon Water Heater - Is Install Much Different ?

[i g norant]

I am going to have a gas WH replaced with an electric Marathon. (N Metro Atlanta GA)
Calling a few HVAC and plumbing companies for installation, most do not install Marathon, even if I supply the WH. The 2 companies that say they have experience with this installation, and have given installation quotes, said I could save money buying it myself. I have found a good deal.
I have not yet looked for an electrician, but I assume I need only a new 220.
Is a Marathon installation that much different?

[hvac1000]

read the manual that comes with the unit. It will explain the install procedures.

[amickracing]

I'm far from a plumber, and have only installed a handful of water heaters in my life (thank god!), but I have to say, there is not really much difference between the different brands, they all hook up the same and work similar.