He lists the Guardsman Blue as OEM Ford for 1964, paint code F. $12.50 for a 2 oz. bottle of Gloss Acrylic Enamel. This is the "authentic" automobile paint, and so will be hotter than Testors enamels. He says the paints are pre-thinned, but you might want to pickup a 2 oz. bottle of his enamel reducer for $3.00.
He doesn't charge for shipping and handling, so while the price for the paint seems really expensive, it ends up costing no more (and maybe less) than ordering from another online store.
Here's a link to the actual color chart for 1964 Fords showing the Guardsman Blue. Note that different monitors show colors differently so what you see may not be 100% accurate.:
http://www.tcpglobal.com/aclchip.aspx?image=1964-ford-pg01.jpg
Personally I would use my Mark I eyeball and get "good'nuff" but that's me. Your desire for accuracy may be different from mine!