[Plugin: WP e-Commerce] Best payment option in Spain

I’m working on a wordpress website for a small boutique in Spain. We are about to integrate the e-commerce plugin to launch the online shop. Having paypal is no problem, but what is the best payment option for the shopper to use credit cards? I understand that Google checkout is only good for US or UK accounts. Thanks in advance!

http://juliakoo.com/

http://wordpress.org/extend/plugins/wp-e-commerce/