Just be aware even a small hps will get pretty hot if not vented right. I have a 150w that has an internal ballast, and a 600w air cooled. They push about the same Watts per inch -/+ 1-2%. The 150w's tent is actually a bit more difficult to manage. It's not that bad or hard to manage, just want to make sure you know, it's going to be way hotter than any led.
I would recommend taking the above advice and making a cool tube for it. I can tell you from experience a Cool Tube will drastically help cut down on your temperatures. I'm able to put my hand on the plate glass of my 600 watt hood that only sits about 3-4 inches away from the light without burning myself.
Good choice in seeds bud. I'll have a lsd-25 in my upcoming grow. You won't be disappointed! Always try to enjoy your grow, and if things get tough, you have a great community to fall back on here. Take care, and have fun! :smoking: