The Region 1 Three Disc Explosive Edition seems to have similar audio and video options and includes the Tarantino conversation and Director’s commentary on the first disc. The second disc has two featurettes. The first, “Train Kept-A-Rolling” (75:21), is a documentary that contains new interviews with just about everyone involved in the film and covers the production in detail. The second, “Back in the War Zone” (13:01), has Castellari revisiting some of the filming locations. The third disc has 18 minutes of soundtrack.
In Region 2 there is also a 3 disc edition, containing the film, the soundtrack and, on the second disc, interviews with the Director (20:16) and composer Francesco De Masi (51:30).
On the basis of the above, the Region 1 SD seems the best choice.
There is also a Region A Blu-ray that includes all the extras on the Region 1 SD, plus two other featurettes: “Enzo’s 70th Birthday Celebration” (7:15) – a reunion with a couple of the film’s stars – and “Inglorious Reunion at the New Beverly” (11:24) – footage shot at a special screening of the film in Los Angeles.