I don't think a 430 watt light is enough for that much space, personally. That's 16 square feet (assuming the 6' dimension is height). That light would cover a 3x3 area, but even then, the periphery would not get much light in comparison to the center. Light drops off proportionally to the square of distance, so double the distance, one FOURTH the light. Triple the distance, one ninth the light, etc. A 1k light would be ideal for a 4x4 area. What you could do, though, is section off your box for now and create two 2x4 areas, and use that light in one of those areas, and add a second light later to the other area. Or sell that 430 later and buy a 1k light, although I would personally just add a second 430, so that you have some equipment redundancy, and you're not totally screwed if one light fails.

For my (flower) box, I went a little overkill and got a 6" 440 CFM fan, which I have speed controlled down to where the noise level is tolerable. And this fan is up top, at the exhaust area. For the air input, I just left it passive, using two 8"x8" Doran darkroom filters. A 4" inline centrifugal fan would be enough though, even for your box (which is twice the volume of mine), but again, I'd use it for an exhaust fan and use passive intakes. I don't really see much reason to have active intakes - just complicates things, more stuff to fail, unnecessary expense, more lightproofing hassle.

It's better to graduate your pot size as the plants grow, which requires transplantation. I understand laziness though. What I do to maximize laziness is start with styrofoam 16 oz. cups (which are easy to razorblade down the side to extract the soil mass), then transplant to 1/2 gallon square containers, then one final transplant to 4 gallon square containers. So that keeps me to just one transplant that's in any way a hassle, and even so, it's not a major hassle. Ideally, it'd probably be better to have one extra round of transplantation in there between the 1/2 gallon and 4 gallon containers, but again, I'm lazy.