Heater Question for the Ole' 74 Project

[jwe648]

Continuing my ever growing project of restoring the Ole' 74, I've riped out the bedroom floor because of wood rot from leaking windows.
In the process I removed the water heater (American Appliance). Although not leaking it looks very tired and the annode is frozen. So with that in mind.. if I break it, I will need to replace it. From what I have learned so far is that, the company is out of business and the only water heater that will fit the hole is a Suburban. Here's the kicker.. my water heater is also connected to the engine coolent to supply hot water going down the road I suppose. I suppose it could also pre-heat the engine for those cold days although, I don't see any pump in the system (or at least I haven't found it).

I do not see that Suburban has a like model.

Are there any other options...within reason?

Jimmy