small grow room maybe 4 gals(discussion)

Ive always been a outdoors kinda guy but have a space not even in my own house id like to grow 3 or 4 gals in. Ill get the dimentions and report back today. The room is with in an attached garage. I plan on putting mylar on all the walls in the room and putting a small circulating fan and 5 gal buckets with fox farm soil. I dont know if i need co2 of something added to the room and id like the most energy efficient yet well working lights. First things id like to understand
1. Lighting for 4 plants(will 1 light handle veg and flower?)
2. Will the room air be ok(dimentions coming today).
Once we determine a good light(s) id like to figure rough monthly cost

One 1000w light can do 4 clones vegged for 6 weeks or so. Co2 is optional, you don't need it but it's optimal. The room air will be fine if you have an intake fan and a negative pressure in the room. If you use co2 you will want the room sealed.

1000w metal halide for veg
1000w hps for flower

Get a switchable ballast that handles both bulbs.

Annnnnd youll be good to go, good luck buddy!