Danny, if you're talking R1 release, there's a possibility you're not out of luck just yet. I think (and someone can correct me if I've got this backwards) that the 25th Anniversary edition got renamed "Special Edition" after a year or so, but kept all its features, including the excellent BBC doc The Fear of God. As I understand it (and I didn't start with DVD until 1999, so I'm not absolutely certain about these old versions), there was a fairly bare-bones edition of The Exorcist released in 1997; the "25th Anniversary" in 1998; the "Special Edition" (25th Anniversary re-named) in 1999; and "The Version You've Never Seen" (with the added footage) at the end of 2000.
So you may want to try your sources again, searching just for "Special Edition" to get the best version of the original film (do check the feature specs, though, to be sure). The only version with the altered (for better or worse, not a debate I'll get started here) film is "The Version You've Never Seen." All other releases are the original.