Grow box

Hello. I'm totally new to growing. and i have a few questions. once again i'm a noob so bare with my ignorance.
I'm building a grow box.
its 8 feet long, 4 feet tall, and 4 feet wide.
Space is not an issue for me at all, so i made my grow box very long i plan on doing a SOG method eventually. I chose these dimensions because its easy to make with factory cut 4x8 sheets of plywood.
Question 1- is 4 feet tall enough for my box?

Right now I'm just practicing with seeds i got from a good bag.
I'm iffy on having seeds sent to my house,

Question 2- what seed sites are safest?
also, anyone ever hear of anyone gettin busted for seeds in the mail from any certain sites?

I'm going to divide my box into two sections
one for veg room the other for flowering
I plan on using 2 4 foot floros and a small number of compact flloros for the veg room But i'm stuck on lighting for my flowering room. I heard HPS is the best for flowering, but I'm not sure if I'm ready to dish out a ton of cash on lighting yet. (especially on my bill)
Question 3- What are my flower room lighting options? (rough estimation of cost would be great)
I plan on coating the entire inside of the box with Mylar, but for now its aluminum foil
I have a few ideas for ventilation, so i'm not worried about that, but i would like tips on nutes for my soil.
Question 4- I have some miracle grow 15-30-15 this worth keeping?
Any help would be greatly appreciated. And i plan on posting pictures of my box soon if anyone is interested.

You should have had HD cut the pieces for you into actual boxes rather than thinking you'll be able to effectively divide a big box. 4ft is going to be too short for flowering, and to flower you're either gonna need $100 worth of CFLs and the hardware to support it OR a HID so check out http://www.1000bulbs.com/High-Pressure-Sodium-Ballasts/ they're cheaper than HTG. Yes HID's cost plenty, but so does running a shitload of floros. Your tube floros should be either T-8s or T-5s otherwise it may as well be a very cloudy day for all your plants. To better use those tube floros try SCROG or some LSTing.

There's seed and strain (and distributor) reviews in the RIU forums, my advice is shop around find what you want then google the site name and ask for a review like "seedbank.com review" and you'll find whatever. Go buy yourself a Visa gift card (buy with cash at the bank, make sure it's international capable) for the cost + shipping and use that to order.

Get your mylar before you assemble your box, it's easier to cover one piece flat, seal the sides with aluminum tape and heavy-duty staples and THEN screw everything together. Spring for the 2mil thick stuff, it's worth the cost in lack of annoyance alone.

To answer your miracle grow question get one thats high in N low in P and K like 20-10-10 and during flowering get a fert thats high in P and K and low in N

Thx fuzzotany. The reason i didnt have the wood precut, was because i have a ton of wood just laying around, and i decided to take up the project of building a grow box. I still plan on going totally CFL. According to my research, if i decide to go CFL i should use mostly 6500k's for vegging, and 2700k's for flowering Correct? If so, does it say right on the box of the bulb?