Indeed, just use the shebang #!/bin/sh (if it's posix sh), and #!/bin/bash if you must use bash functionality. There is no reason to not use a different interactive shell.
Please use #!/usr/bin/env bash if you're using bash. It seems more common to have env in /usr/bin than it is to have bash in /bin. On BSD systems, bash is often in /usr/local/bin, and on macOS the user often has a more modern bash in /opt/homebrew/bin or other package manager directory.