I prefer a negative ion generator for constant use. The negative ions will help stimulate good neurotransmitter production for a more balanced feeling. By default the machine also produces small amounts of ozone. Higher amounts can be problamitic for sensitive individuals. If I were you I'd consider a negative ion generator such as the IG-700 by Electro corp.
For ozone treatment of air (done while noone is around) I prefer a high output machine. Great for reducing pollutants and great for mold problems.