I think that there are some good companies who sell excellent heads.
For instance: Wolff, Hornet, making extremely well sculpted heads. I don't know if they make US Infantry heads, but some putty and plastic sheet will do the job.
Marc
Thank's for getting back to me. Still looking around but in the end, Historex is probably my top option.The Hornet 54mm ones are great. To me the Historex ones are good, too. Milminwh has some as well although I don't have any of them myself.
Keith