They got ride of the aluminum pots because they stuck like mad, or nowadays some get ride of them because they are coated in teflon
You can always get one of the Marathon water heaters
Because they are curved a bit, I support my A7 bracket from the rafters from above. The u bolts are on as just a back up in case I crash into the thing or something.
The marathon also has a inlet relief valve built into the coldwater nipple which makes a tight u bolt fitting difficult.
Here is the hylomar info
Hylomar Sealant