Leaf litter, Black film cans laid horizontally on the substrate, Petri dish or deli lid under coco hut, mist and feed, most important; patience . At 9-10 months old they are just reaching breeding age. It's harder to get them to stop once they get going.
My group lay everywhere! They lay on plants, leaf litter, petri dishes, film canisters. They have laid so many that I don't remove any eggs anymore. I agree and would be patient and give them more time. Just because the male is calling, doesn't mean the female is ready. Plus my personal experience is that they breed more readily in groups of 5 or more than in pairs.
They'll take a little time to adjust to the new vivarium. Once they're comfortable, your male should start calling with more frequency. My vittatus lay most of their eggs in the leaf litter. I have a water feature in their vivarium, and allow the tadpoles to develop in the vivarium (I add tadpole bites to the water feature once a week when I know there are tadpoles in the "pond"). My vittatus seem to really like moving water...and often will deposit the tadpoles near the end of the "stream" in their vivarium, rather than in the still far end of the pond.