I bought the MST3K version of this some years back on an auction on Rhino VHS. I wish they'd get the rights thing settled and release this and War of the Colossal Beast, its sequel, out into one of the MST3K boxed sets on DVD.
Joel and the 'Bots were in rare form with this and Colossal beast.
I picked up a copy on RetroFlicks.com. A double feature with War of the Colossal Beasts. Original versions not MST3K versions. According to RetroFlicks info links, these are not bootlegs or pirated copies.
AMAZING COLOSSAL MAN and WAR OF THE COLOSSAL BEAST were available on VHS from Columbia in the early 90s, along with INVASION OF THE SAUCER MEN, HOW TO MAKE A MONSTER and a few other B-movie gems. I have them in a box somewhere and I think you can still find them on Amazon.com.
DVD Drive-In dotcom posted a news item a few months back saying Mackinac Media had plans to release TACM on disk. However, nothing more has been said about it, and a cursory search of Mackinac Media's site turns up nothing.