Thanks for the input and ideas, everyone! Sorry it took me forever to respond again. Mr. Puppy is at his breeder's for a bit till I can have him here. Before he went back I started calling him Pip, but I'm not sure that's going to stick. I really like Kite on paper, but I'll have to try it out to see if it feels/sounds right.
I'm debating trying to come up with a name that has more meaning behind it. It wasn't something that I knew when I named him, but the rowan tree is traditionally a symbol of protection, and has a ton of folklore around it. A guardian tree is a very appropriate namesake for my ESA, so I think it would be cool to pick something like that out for my SD prospect. The ash tree is also associated with protection and healing, for example. "Rowan" and "rune" have similar roots - Tiwaz might be a good name. I dunno... I'm struggling so much with naming this puppy!