[A/S] replacement hw heater and patching the skin

["C. Hale" <chale@xxxxxxx>]

Hi All,
I must replace my old Vaillant demand hw heater for a new functioning
one.  The space is really small and not too negotiable.  I'm looking at
6 gal Atwood and Suburbans.  I'm inclined to get the Atwood because you
can replace its tank if needed and is slightly smaller front to back.
The 3 gal Suburban is smaller, but more costly and not available in
Canada without shipping in from US.  At this point it would be
considered a special order and incur all shipping and duty costs.  
 
Is there a substantial difference between the two brands?  I'm going the
older pilot light technology.  
 
Either choice means changing the present opening... the new hw heater
doors are wider and shorter, so I'm also looking for advice about
patching or filling in the remaining upper unused opening area.  
 
If there are better hw ideas, I'd like to hear them.  Thanks for your
advice.
Cindy 
59 Traveler