My heatpads are on 24/7, but my lights are on a timer.
Based on my personal experience, (I may be just lucky), I have had 1 reptile heat pad die on me, but the human heat pads I have been using for over 4+ years which are on 24/7 are still going strong. I believe that either type of pad will meet your needs. If you are worried about a fire/electrical hazard, purchase a cheap analog thermostat.
Hope this helps!