I use Atra's D7's, but I don't know if they are available anywhere now. You can try the model repository at Starfleet Universe. As I remember, Fleetdock 13 has some D7's. I can't remember who made them, but they are very, very similar to Atra's, at least in over-all appearance. There was also a smaller D6 by the same author. I think there is only a Klingon version, but since the ships are by the same author and share similar designs, they might use the same or similar textures, so it might not be too much work to transfer the Romulan markings from the heavy cruiser to the light cruiser.