This script converts wordpress' default variable product's select to a bunch of swatch options. Style as you need it.

convert-wordpress-variation-select-to-radios.js

// this is super hacky, but it gets the job done
// this may be placed at the end of your theme's woocommerce/single-product/add-to-cart/variable.php
// or in the appropriate js file that you load via wp_enqueue_scripts
// if you want to be clean about it
(function($) {
  var $variationsForm = $('form.variations_form');
  $variationsForm.find('select').each(
    function(i, select){
      var $select = $(select);
      $select.find('option').each(function(j, option){
        var $option = $(option);
        if (!$option.val()) { 
          return;
        }
        var variationObj = $.grep($variationsForm.data('product_variations'), 
          function(variation) {
            return variation.attributes.attribute_pa_finish === $option.val();
          }
        )[0];
        // Create a radio:
        var $radio = $('<input type="radio" />');
        // Set name and value:
        $radio.attr('name', $select.attr('name')).attr('value', $option.val());
        // Set checked if the option was selected
        if ($option.attr('selected')) $radio.attr('checked', 'checked');
        // Set the radio's attribute_name
        $radio.attr('data-attribute_name', $select.attr('data-attribute_name'));
        // Set the radio's attribute_id
        $radio.attr('data-attribute_id', 
          variationObj.variation_id
        );
        // Make sure to set the variation id on the hidden field if the option was selected
        // Lame wordpress for the win 
        if ($option.attr('selected')) {
          $variationsForm.find(' input[name="variation_id"]' ) .val( $radio.attr('data-attribute_id') );
        } 
        // Insert radio before select box:
        $select.before($radio);
        // Create the image swatch
        var $swatch = $('<img />'); 
        // Set the image swatch's source
        $swatch.attr('src', variationObj.image_src);
        // Grab the price html from the variationObj
        var priceHtml = variationObj.price_html;
        // Insert a label:
        $select.before(
          $("<label />").attr('for', $select.attr('name')).html(
            // combine the swatch html and the priceHtml
            $swatch.html() + priceHtml
          )
        );
        // Insert a <br />:
        $select.before("<br/>");
      });
      $select.remove();
    }
  );
  // on select of a radio button
  $('form.variations_form input:radio').change(
    function() {
      if (this.checked) {
        // set the variation id on the hidden field
        // again, lame wordpress =)
        // but, we got it figured out, which is key
        $variationsForm.find(' input[name="variation_id"]' ) .val( $(this).attr('data-attribute_id') );
      } 
    }
  );
  // wordpress fucks with the add to cart button,
  // thinking we forgot to add variations
  // but, we'll tell it what's what
  $('.single_variation_wrap').show();
}(jQuery));