Initial Ideas for a film opening

I like the idea of working on a film that is quite dark and sinister, so the horror/thriller genre appeals to me but also so does "Film Noir" as I really enjoy these kind of films like The Maltese Falcon and even Casablanca. I personally enjoy a lot of psychological horrors and films from the mid 20th century, I look up the 100 best horrors films and here are some of the ones I like or would like to see the most:

The Shining
Psycho
The Exorcist
The Omen
Don't Look Now
The Wickerman
An American Werewolf in London
Dawn of the Dead (1978)/ Day of the Dead
Friday the 13th
28 Days Later
The Howling
Misery

Eternity
Some ideas I have for my film have some links to vampire films, maybe somehow linked with film noir, like a vampire detective, could be portayed in a trench coat and trilby hat smoking a cigarette and maybe coloured contact lenses and vampire teeth to signify he is a vampire. Maybe we could have flashbacks of crimes he has witnessed or how he became a vampire.

Obsession
Another idea I had weas of a pyschological horror film, maybe the main character is planning how he is going to kill someone, maybe a young attractive female, stereotypical representation. Maybe sitting in a basement or darkly lit room with pictures on the walls and then it shows him leaving with maybe a knife in his pocket and the film ending with the door closing behind him.

Solo
I also like the idea of a post-apocalypse sort of film like 28 days later by having a character waking up and there being no one else around and walking around a deserted town and then being chased by zombies or her/him picking up a newspaper saying what has happened in the headline.

Or maybe a film about a schizophrenic murderer who wakes up with blood on his hands and cannot remember what has happened and he finds out he has gone on a murderous rampage and killed people and stored them in his warehouse, shed, etc.