I know this thread is older, but I feel like I could chime in.
I just sent a bird to Ryan Scearce at Billingsby Road Taxidermy in Paris TN.
I have heard great things, and I have seen his work at the NWTF convention in Nashville.
He sent me directions on how to freeze it, and I followed those and it went very well. As far as shipping it, he told me to ship it 2 day and it would be close to thawed enough to skin when he gets it.
I took it 1 step further and wrapped the bird in home insulation prior to shipping. He said it was frozen solid when he got it after 2 days in a hot truck/warehouse. Shipping cost me maybe $50.
I am hoping to get the bird back around Spring of next year, but he said he usually has a roughly 6 month lead time.
Ryan and his business are both on FB, and he responds to messages very well.
Hope this helps!!
Josh