Gulp task with different source depending on arguments

You were on the right track with your second try, just needed to utilize a bit of DRY and closures

function createTransformTaskClosure (destination) {
    return function () {
        return gulp.src(config.sourceJSX)
                   .pipe(gulp.dest(destination));
    };
}

gulp.task('dev', createTransformTaskClosure(config.output_development));
gulp.task('prod', createTransformTaskClosure(config.output_production));