Hey Lindsey,
I've kept whites for years - up to 5 at one time in a very large tank - so I should be able to help a bit.
You're right - your day time temp is a little too low. Whites can easily handle temps in the mid to high 80s.
Night time temp isn't bad. You may just want to try a blue night bulb instead of a red. They sometimes work better.
For day time heat, I've only ever used 60W incandescent household bulbs - not the new energy efficient ones, the old, heat emitting ones.
Multiple bulbs or higher wattage if the tank was really big, but that was it.
And though I've never personally used the ceramic heat emitters before, I hear they work very well.
To test, (if you can) set the ceramic heater up away from the tank, put a temp gauge beneath it and watch how hot it gets. If it's a good temp, use it in your tank.
You can do this with higher wattage light bulbs as well.
Hope that helps.
-ry