I think you may be disappointed if you save those two for a special occasion. "Sabotage" is ok and it's fun to see how cute the old lady from Beetlejuice used to be...
... but Jamaica Inn is
really bad. On paper it should be amazing: the source book by Daphne Du Maurier is a pretty good potboiler with a lot of atmosphere, Charles Laughton was at his peak, and Maureen O'Hara was beautiful, but none of it comes together. It's terrible. What makes it even more surprising is that Hichcock was able to make the somewhat similar movie "Rebecca" into a classic just a year or two later.
There is a made for tv version of "Jamaica Inn" from 1983 that is much better, imo. It stars Jane Seymour and Patrick McGoohan.
Have you watched any episodes of "Alfred Hitchcock Presents" of "The Alfred Hitchcock Hour"? Those may make some good Halloween viewing.
A few good episodes off the top of my head:
Alfred Hitchcock Presents:
Revenge
Where Beauty Lies
Specialty of the House
Man from the South
No Pain
Apex
Poison
A Man with a Problem
The Right Kind of House
None are So Blind
The Alfred Hitchcock Hour:
The Jar
An Unlocked Window
A few more non classic movies for the less discriminating:
Deathdream (1972)
The Entity (1981)
Martin (1977)
Dead & Buried (1981)
Razorback (1984)
Rituals (1977)
Society (1989)
Slither (2006)
Dead Heat (1988)
Long Weekend (1978)
Suspense:
No Place to Hide (1981)
Murder by Natural Causes (1979)