Hi Brantingham,
Thanks for your update.
We have prepared a simple sample to achieve your requirement("The selecting a value from the first Template Column and then change list of selectable values on the second template column") and the same sample can be downloaded from the below link.
Sample: http://www.syncfusion.com/downloads/support/directtrac/general/MvcApplication12-1315432859.zip
Please let us know if you need any further assistance.
Regards,
Hariharan J.V.