I can't seem to edit your photo's-it's a front view-go stand in front of your room and look at it. I recomend removing the little cubby, where you want to put the squirel cage, and replacing it with a door to your flower room. partition the room to make your veg-and leave the existing door.
I sduggested the hydro system because it will fit in your space-and you should be able to get 6 grow sites from it(add or remove pots)-as I mentioned in my other post-when you said ebb n flo-I thought ebb n gro-comes with 6 pots and a 30 gallon resevoir barrel-it's large and expensive.
I also think that you will find that after you price everything out, and spend the time building it-it will be very close to the same cost.
My lighting recomendation is also for cost-one ballast-one bulb-one fixture.
The minigen co2 unit is the most cost effective unit unless you can find something else on sale-but it is also very small-good for your space.
I don't know what kind of condition your basement is in-but here, they are mostly moldy and musty-not what you want for ventilation for your girls. Thats why I recomend sealing the room for co2 and using a frewsh air source from outside. Also-if you use the fresh air source to cool your lights-you are not venting any smell-and don't need a charcoal filter($$$).
I grow in a 4'x9'x6' canning cellar in my basement-I make these recomendations from my own experience growing in a basement,(a crappy one at that).
This is my grow-week 7:
http://www.marijuanapassion.com/forum/showthread.php?t=63049
