8 by 10 can evaporate very quickly. if the room doesnt have AC already, your going to want to figure in about 7-10,0000BTU's per light. so the more lights, the bigger the AC unit. that takes up place. And then you need humidity control, and if your using co2, you enter into an all new ball game. Filters take up space, and if you run aircooled lights, you have hoods and ducting that all take up space.
your size of plants are HUGE bud. your going to loose height for sure if you go that big before flowering. so hoods with only get in the way. but keeping good air movement without burning the plants is going to be a big concern as well. I run a similar set up. my room is a 9 by 7 by10. I run three 1000w lights in air cooled XXL Mag Hoods. they are huge, and keep very cool. i run co2, I have a 30,0000btu AC and a dehumidifier. there is a heater in their as well for when the lights go out it does not get to cold. I veg plants for 2 weeks until 8-12" in height and then flower. I put 15 under each light and each group of 15 is in its own flower schedule. I swap 15 out every three weeks. that way my veg room and cloner are always producing. and i flower on a 9 week cycle. my end result are nice 3' plants with 2-3 ounces a plant. and they are all still nicely spread out that air circulation and co2 distribution is timely and efficient. if you pack a bunch of giant plants in their, you start running into PM and mold issues. and that ALWAYS sucks.
good luck bro, and growing with this much space always makes it more fun. i just cant wait to expand. bigger right now to me sounds crazy, but sounds like a ton of fun.
