when u start growing it becomes a hobby. And like any other hobby you want the best tools, or items, or instruments for the job. Myself and other growers for example would use funds after the first grow of plants to say "upgrade" items on their "grow rig".
Lighting is always a good and crucial upgrade, but comes at a cost for 2 ways. Heat and Ventilation. Need to circulate air for many reasons. Which means you may have to put on attachments to your rig like fans and tubes.
Metal Halide (MH) is your vegging light. Blueish color. Youll see large ones on outside of buildings sometimes. Usually those are around 1000watts for reference.
High Pressure Sodium (HPS) is your flowering light. That famous orange color tint. More of your street light type color usually. Those are also 1000watts usually.
A Ballast is needed to give the MH or HPS light its power. These create noise and heat often but not super loud or nething but do give good warm temps at times. so keep far from plants if you can.
If you use those lights you are going to have heat as you know with just the 70watts. i will tell you from experience as a new grower also and have met other growers with professional like setups, and if you ever just want those fatass dense gooey sugary coated nugs then you need these light types.
I will say 400 watt minimum is efficient for getting big colas and nugs. I hear 600w is the standard basically for pros along with 1000w.
the recommended lighting for my 3x3x7 tent is a 400watt light. I have to air cool it because i will be in a tent (ebay 90bucks). They can make ur grow room 90+ degrees, thats not good you want 70f-80's
some people dont need to however. It depends on your hood.
A Hood is gonna usually reflect light and focus it on a certain large area. Some can be air cooled allowing you to cool the light bulb and the grow room, while filtering the smell too. And lets you move the light closer in.
A Reflector is not a hood. Its like a wing usually. large piece of polished metal bent around. these usually are not air cooled like the hoods.
Problem is, only a few options for the lights as you cant just plug and play the light MH and HPS lights into the same light setup. They require different stuff. So most people get the HPS first so u can flower awesome. They have bulbs that are conversion so it is half MH and HPS and work well ive heard. then you HPS the rest of the way.
Some digital ballasts and good socket fittings can support both Bulbs at the same wattages. a 400w MH and a 400w HPS. But those can get pricey.
Soil or Hydro?