Just saw you are in the Carolinas.
You must know of Unifi,
http://unifi.com/un_product_ourbrands.aspx
They have a 4t7 thread made of silver than can be combined with anything else to create a metallic yarn.
Not sure if cost competitive, but it’s local in Greensville.
Not Greensville, but Greensboro, NC.
That’s a performance yarn with literal silver in it for antimicrobial properties, like SilverMax. It would be cost prohibitive for this application.