I'm starting to lean towards trying to find a used LED that pushes true 600 Watts and at least 1100 PPF. I don't want to miss out on the benefits of LED. My budget for my initial equipment buy was to try to stay under $500, and I'm already $100-in with the tent I bought yesterday.
I've read where some that have went with HPS have had fire hazards from them running hot, and a few hundred bucks isn't worth the added concern about that, plus the energy savings are very attractive as well.
I understand that it's a trade-off economically, comparing HPS vs LED, so finding a used LED at the desired specs seems like my best move for right now.