you dont really need so large pots for autoflowers (well, depending on the autoflowers)
better to start off in smaller pots.
its also hard to tell how large a system youd need for those plants, i dont know how large they grow.
6 plants in 3 gallon pots would require at least a 400w hps or a shitload of cfls.
i need more info, feed me
how large a space do you have?
what are your needs in yield? how much bud do you need?
btw, all that you want to know, Is on the internet, search and google are fantastic allies. you should use that as well.