We don't provide adapters but I did a quick search on google and found a 8-pin DIN to 9-pin D-Sub adapter. NI ELVIS has the 9-pin D-Sub connection on the protoboard and so this would work perfect. I've included a link below to an adapter.
The adapter I've linked to is male on both ends; NI ELVIS has a male D-Sub connection and so you would need a female 9-pin D-Sub to actually connect to NI ELVIS. There are 9-pin D-Sub male-to-female converters. I hope this helps. Have fun with NI ELVIS.
Link to Adapter
http://www.buy.com/retail/product.asp?sku=10029458
Regards,
Todd D.
NI Applications Engineer