I like the combination of HPS and LEDs, they should compliment each other well. My first choice would be to combine your 250w HPS with a Procyon 100. I would bolt them close together and mount them on a light rail. This will spread out your light to cover the 5' length easily, plus it spreads the heat of the 250hps around some. Light penertration is so much better since the "angle of attack" of the light to the plant changes constantly, allowing light to hit ares that normally would be shaded with a fixed light. (it's also fun to watch!)
Oldmac's suggestion above is not to be discounted. I wouldn't worry too much about not being able to sweep the entire length of the grow as the good rails have a timer for how long your lights dwell at the end of each pass. A huge advantage to this scheme which I forgot to mention is: less lights = less heat, less $$, less electrical usage.