We want to develop a new shopping cart for our web store, and I am having a hard time deciding which candidates to seriously consider. Our product has a lot of options that have to be configured (see example http://secure.srginc.biz/product.php?brand=sa&prdID=44532 ). I need something that can be easily adapted to handle complex products. Also, I need to be PCI compliant. Would you recommend something like OSCommerce or X-Cart, or anything else? I need all of the constructive criticism and advice I can get...