I dont have personal experience with HPS, but from what I've read (and someone correct me if I'm wrong), you should be fine. Make sure to start your light out far away and move it closer daily, watching your plants for signs of stress or burn. That should give you an idea of how close you can keep your light. I don't know exactly how far away you should start but id guess 30-36". Once again, no personal experience here, but from what i have read that's how id do it.
Im using CFL and T5 for flowering for sake of heat, power consumption, and space limitations. Someday when i have a larger grow area, ill definitely go to HPS.