An off brand mini split like pioneer will cost $6-700 and will pull 5 amps. The one you have will work fine it will just cost more to run. A propane tank will last a month or more for a co2 burner and they don’t stay on long so it’s not as much a heat influence as listed. A co2 bottle would be better if you have a convenient place to swap bottles and you can get it to last a month. The hoods are vented from outside and to the outside. You could put the dehuey in the garage and just exchange dry air from the garage when lights are out. As long as you aren’t running beds the lights and ac will keep it dry enough during “daytime”. A clone tent would save you some time in getting each run reset. Like you said you could probably just veg for 3 weeks in the room after you got them out of the cloner. One 315 cmh covers 16 3 gallon pots in veg and they love it about 4 feet over their tops.