As a starter you could do a lot worse than this lovely collection.
https://www.amazon.co.uk/Westerns-Co...d%2C538&sr=1-3
You get John Wayne, Clint Eastwood, Gregory Peck, James Stewart, Richard Widmark, Henry Fonda, Sam Peckinpah, Warren Oates, Ernest Borgnine, William Holden. It's a terrific set.