I'de do the same.. most shops don't carry them as they are an oddball and require more attention then some flakes tossed into the tank.. but I have yet to be unable to source one if/when I've wanted them.
This one is pretty epic but not the only One I've come across.... and I've been tossing around getting another armatus myself but I really want to try and focus on my fire eels...I'll see if a can't break that size record next lol.
I've seen a few that look bigger but that's the only one I've had anything to compare size to anything. and a history given ect... There is another picture thread of him that shows him poking out both ends of a 4' PVC best I can gauge it so I do believe this fish is pushing the 48"+ mark.. thought I had linked that thread >.<...