I don't know what kind would be good, but I'll tell you what happened to me.... I tried just using a straight nail and angling it so that the machine didn't fall off the all... apparently I missed the stud and the thing fell off and smashed my Hoover 28 all to pieces.... I was mad! So, just be careful, and don't put anything "good" or vintage or rare underneath!
That is the secret-if you hang the Oreck or anything elese on a wall for that matter-make sure the hook is firmly fastened into a STUD!!Plaster board alone will not support ANY weight.