Anyone ever used this? I bought a Utilitech Shop light to mount my 24" bulbs in Toothless enclosure, But this would allow me to streamline them higher in the tank.
I use the regular non-lightcycle version of that fixture, and its great. The light cycle feature is mainly a gimmick, and not worth the extra cost over the standard version. Make sure to buy the version that most closely matches the wattage of your bulb. IIRC, these fixtures come in 20w, 30w, and 40w varieties and work with either T-8 or T-12 bulbs. You need to have both bulb locations filled however, as it won't work with only one bulb installed. So use one UV tube, and another standard non-uv tube for extra brightness.
The dimming effect is honestly somewhat minimal on the fluorescent tubes, but the unit you pictured does dim the lights somewhat when turning them on and off.
The regular light cycle unit may meet your needs somewhat better, as BadCon suggested.