I think you are trying to say you (hahaha), don't think you should have to explain that you didn't think the 16-5gal buckets will fit in a 2'by3' space. So silly of me, of courseI should have known about your mistake and I should have known you were going to use 5 gallon pots. Hahahaha. Look dude, you are right they will get bigger, if you let them, they do not have to be transplanted several times unless 2 is considered several and the experts recommend that you use maximum 3 1/2 gallon pots unless you want to inhibit growth of the above ground part of the plant.
Soo... now that we all understand you have some more research to do lets get started, ok??
All of this talk about sunlight and maximum and I did the math is confusing, at least it was to me. And then cloning and lst and sog etc., etc. Lets try to make some progress, one area a time. The first decision would have to be your growing medium, what you are going to 'grow' your plants in, sound like you have decided on soil, which makes the systems you might have chosen, ebb and flow, dwc, nft etc
bad choices, they don't work well with soil. Soil is easier to work with at first, I don't think flood and drain is that difficult, flithy fletch swears his dcw is easy to learn as well. You won't have to worry about any of those for now.
The best source I have seen for a new soil grower, with all of the information you need to get growing is SeeMoreBuds new book, "Growing Marijuana For Less". If 8oz of bud from three females isn't enough for you then just multiply, do the math. Need two pounds, invest $400.
The system to cool 8-1000 watt lights would cost more than that.
Read some journals. My space isn't exactly the size of yours, I have a little more room, but some of that is taken up by the heater and you may not need that. And I'm not growing in soil, I do have some discussions about lighting and options, how to get a 'system set up' for a 'perpetual harvest', things like that that you may find of some interest. If there is a mistake to be made, I have made it. Its like Prego,"Its in there".
You will of course want to read some 'soil grow' Journals, I think widowmaker has one, I'm not sure if Garden Knowm has one here or not, he wrote the book, He is SeeMoreBuds. I have to admit I have had to skip all of the soil grows to learn more about the system I am using.
Keep one thing in mind while you are planning this.
A GROW ROOM WITH NO ROOM IS A PAIN IN THE ASS!!
leave room to walk around and tend your plants that isn't under a furnace. VV