I took Zarith's advice in the end and ordered mine here
http://www.thrauma.it/dettaglio.php?dettaglio=dvd&id=7
says it runs for 102 mins which is slightly longer than the US 89 mins listed on imdb.
after a bit of italian-english correspondence i payed via paypal and it turned up two weeks later. seems like a good website and in my experience most italian dvds have english subs too!