Default Template

did you ever figure out how to do this? I am wondering the same thing…

I just figured it out, but for me I am using gravity forms and was able to set the custom field for the post template to the post template name I created.

You may need to have this installed as well for it to work:
https://www.ads-software.com/support/plugin/gravity-forms-custom-post-types

Screenshots here:
https://www.dropbox.com/s/gqnstm9mzyct9z0/Screenshot%202014-03-03%2016.32.31.png

https://www.dropbox.com/s/m95sk359drxtgwg/Screenshot%202014-03-03%2016.32.55.png

Hope this helps someone else as much as it did me.