gistfile1.php

add_action( 'customize_register', 'slug_customizer' );
function slug_customizer( $customizer ){
	
	$sliders = array();
	
	if ( class_exists( 'Soliloquy_Lite' ) || class_exists( 'Soliloquy' ) )
		$sliders['soliloquy'] = 'Soliloquy';
	if ( class_exists( 'MetaSliderPlugin' ) )
		$sliders['metaslider'] = 'Meta Slider';
	
	if( !empty( $sliders ) ){
		$customizer->add_section( 'slider_selection', array(
			'title' => __( 'Slider selection', 'slug' ),
			'description' => __( 'Use an id and the slider ( if more than one )', 'slug' ),
			'priority' => 21 ) );
		
		$customizer->add_setting( 'slider_name', array(
			'default' => '' ) );
		$customizer->add_setting( 'slider_id', array(
			'default' => '' ) );
		// setup select choices
		foreach( $sliders as $slider => $name ){
			$choices[ $slider ] = __( "$name", 'slug' );
		}
		$customizer->add_control( 'slider_name', array(
			'label' => __( 'Choose a slider', 'slug' ),
			'section' => 'slider_selection',
			'type' => 'select',
			'choices' => $choices ) );
		$customizer->add_control( 'slider_id', array(
			'label' => __( 'Use the slider ID', 'slug' ),
			'section' => 'slider_selection',
			'type' => 'text' ) );
	}
}