Computer customization shop Computer Customers is now offering color anodized third-generation iPod shuffle units, as well as various metal plating options. The company is charging $129 for a “standard” anodized iPod shuffle 3G, while “polished” anodized units run $30 more. Also available are a number of metal-plated units, including a chrome model for $149, copper or black nickel units for $169, 24kt gold for $179, and white…