A Radeon HD 6670 should fit the bill
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007709+600083901+600144219&QksAutoSuggestion=&ShowDeactivatedMark=False&Configurator=&IsNodeId=1&Subcategory=48&description=&hisInDesc=&Ntk=&CFG=&SpeTabStoreType=&AdvancedSearch=1&srchInDesc=