The Louvin Brothers are great--probably the most respected country / gospel brother group (there are many) and proponents of "high lonesome" harmonies.

I hadn't heard of giant gospel musicians, but I do have a collection of "little people" gospel, including this one: https://www.discogs.com/release/9441405-Little-Evelyn-Talbert-So-Small-Am-I/image/SW1hZ2U6MjU4OTY5NDQ=