You will need at least 30Watts of light per square foot. They are auto flower. so they dont really have a veg/flower... run 4 plants in a 4x4 area max
With autos you can get away with a liittle bit less since your lights are on at least 50% longer per day. 20w should be sufficient. If you over light autos they may stay small and not stretch out.
Cant say for sure cause ive only done autos outdoors but they seem to benefit from a targeted spectrum. Doesnt mean go buy blurple though but a nice enhanced spectrum would probably do well.
With autos its a mixed bag, some of them are shorter and faster and some take longer but gget bigger and yieldier. Since you got a big space id suggest having a raised sectiion for the smaller ones.
Id start lighting just a section of that space if this is a learning experience. If you feel it will be complicated keeping the space heated to 81F during winter time you could get a mix led and CMH. In my knowledge CMH is the easiest light to grow under. It also means you can change Up spectrum with bulb changes.
As for the led lights it depends on your budget.
I allways suggest diy: its quite easy nowadays, makes leds affordable and designed to your needs, but mainly its incredibly satisfying growing your own weed with your lights and beating your own records.
