Yea, I think that should work, although I don't have any experience with CO2.

The main thing you should worry about is the difference between lights on and lights off. The most ideal is 75F on and 65F off. In your case you want to watch that there is not too much difference between the two. I would say it should not be more than 10 or 15 degrees difference, or your plants will suffer - they really tend to stretch if there is too much of a difference. And when they put their efforts into stretching they are not producing what we want

sn