Nobody suggested running them in phases? It sounds like starting 2 or 3 plants a month would be ideal for this situation. Especially since they're autos, and wouldn't require changing light cycle. Being new myself, I would fear making a mistake and ruining a full grow area that large.
I would suggest starting 3 plants. Learn with them, get the feel for your grow area, and make whatever changes you need to along the way. When your first plants reach about a month old, start 3 more and so on. This will have a ton of benefits in the long run. You can space out buying your equipment a little, and even decide to buy different if you're not happy with your original purchase. If you're lucky enough to get your original 3 to harvest, that's a project in itself. Just my thoughts, there are others here with much more experience. Best of luck with your grow!