Luis,
Most of the shields you will find in designs will be customer shields, where the shield manufactures will custom make you a shield to fit your application. There is a pretty substantial "Engineering charge" for this type of work. So if, you can live with a standard of the shelf design I recommend starting by looking at the inventory of your favorite distributor.
Here is a page of the shields from Digikey.
http://www.digikey.com/product-search/en/rf-if-and-rfid/rf-shields/3539677?k=shield
Regards,
Thomas