I've had very good experiences ordering from
Shocking Videos. I've gotten everything from ultra-rare Andy Milligan films to an uncut (HA!) copy of the notorious NIGHT OF THE DEMON (1980) from this guy. Reading the descriptions of the films is entertaining in itself.
It really seems to be a one-man operation so don't expect to get your order super quick.
WARNING! The site is definitely not safe for pregnant women, children, people with back problems, or work. The little intro video is great but contains lots of gore and nudity, usually in the same scene.