This field accepts an associative array as a source and handles FoxyCart value encryption if it's needed.

FoxyStripeDropdownField.php

<?php
/**
 * Created by PhpStorm.
 * User: nhorstmeier
 * Date: 4/1/15
 * Time: 9:40 PM
 */

class FoxyStripeDropdownField extends DropdownField{

	public function Field($properties = array()) {
		$source = $this->getSource();

		$controller = Controller::curr();
		$code = $controller->data()->Code;
		$newSource = $source;
		$updated = array();
		foreach($newSource as $key => $val){
			$updated[ProductPage::getGeneratedValue($code, $this->getName(), $key, 'value')] = $val;
		}
		$source = $updated;

		$options = array();
		if($source) {
			// SQLMap needs this to add an empty value to the options
			if(is_object($source) && $this->emptyString) {
				$options[] = new ArrayData(array(
					'Value' => '',
					'Title' => $this->emptyString,
				));
			}

			foreach($source as $value => $title) {
				$selected = false;
				if($value === '' && ($this->value === '' || $this->value === null)) {
					$selected = true;
				} else {
					// check against value, fallback to a type check comparison when !value
					if($value) {
						$selected = ($value == $this->value);
					} else {
						$selected = ($value === $this->value) || (((string) $value) === ((string) $this->value));
					}

					$this->isSelected = $selected;
				}

				$disabled = false;
				if(in_array($value, $this->disabledItems) && $title != $this->emptyString ){
					$disabled = 'disabled';
				}

				$options[] = new ArrayData(array(
					'Title' => $title,
					'Value' => $value,
					'Selected' => $selected,
					'Disabled' => $disabled,
				));
			}
		}

		$properties = array_merge($properties, array('Options' => new ArrayList($options)));

		return parent::Field($properties);
	}

}