Hi Paul,
Thank you for your interest in Syncfusion products.
We are able to understand the requirement. In order to apply border to the custom path you can use the stroke property in the CustomPathStyle. Following is the modified CustomPathStyle for setting the stroke property.
Following trigger can be used to include shadow when the node is selected:
I have created a sample based on your requirement .Kindly find the sample in the following location.
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=NodeFeatures2131004435.zipPlease let us know if you have further queries.
Thank you,
Deepa V