Sounds like you'll have to try a few runs with your plant count and figure out the best config/method as you go. You pretty well have to do that with any new space. Once you've done a few runs you'll be able to tweak and dial it in to maximize your space. Your challenge is that 600 cool tube. If you were starting from scratch the suggestion by
@greasemonkeymann of LED's, COBs specifically would be your best bet. They're a heavy initial investment but will pay back over time and allow you to use more of the height, so even faster pay-back. 400w of 3590 COBs would match that 600, you'd be looking at $800 - $900.