Hi Andrew - I got my hands on the Taron-Turuberan book you mentioned. There are 14 pages on this monastery. I've added the description of the location onto Armeniapedia, but I don't know that it sheds much more light on this. Maybe in google earth (using the terrain feature) it would be possible with all these random bits of information to find the spot.
There is more info about the monastery in both texts, but it's a fair bit of text. Can you by chance read Armenian?