Hi,

Here are two topics, where we’ve explained, how to change the cart icon:

http://support.themeburn.com/topic/cant-change-cart-icon-how-to-customize-it
http://support.themeburn.com/topic/change-cart-icon-shoppica-2

You can combine this tutorial with a category or/and store detection to generate different cart menu ID.

Category detection:

http://support.themeburn.com/topic/different-logo-per-category

Store detection:

http://support.themeburn.com/topic/customize-top-navigation-on-a-store-by-store-basis

You can find the cart menu code in catalog/view/theme/shoppica2/template/common/header.tpl:

<?php $cart_contents = $tbData->getCartContents(); ?>
<div id="cart_menu" class="s_nav">
  <a href="<?php echo $shopping_cart; ?>">
    <span class="s_icon"></span>
    <?php if ($tbData->common['show_cart_label'] == '1'): ?>
    <small class="s_text"><?php echo $tbData->text_cart;?></small>
    <?php endif; ?>
    <span class="s_grand_total s_main_color"><?php echo strip_tags($cart_contents['total_sum']); ?></span>
  </a>
  <div class="s_submenu s_cart_holder">
    <?php echo $cart_contents['html']; ?>
  </div>
</div>

Hope this is what you are looking for.

Best,
ThemeBurn team