Hi pippoodle
The cooler temperature is more to your peppered corys' liking than the warmer. I'd be very surprised if you don't see more eggs soon.
Since you have to buy something, why not pick up a plastic specimen container that hooks over the side of the tank to hatch the cory eggs. It's cleaner than a net and you can easily stick the eggs to the sides. Once they hatch they will need to be moved into a small tank anyway. Or, skip that and stick the eggs right into the tank. If you group them together, you can put an airstone under them to minimize loss from fungus. If you put a thin layer of sand on the bottom they will be all set as soon as they hatch.