Grow cab question

im planning on building a grow cab out of that 48in multi purpose for lowes for 109 that gets talked about on these forums alot. my question is how best could one make it a dual mother/veg and flower cab. the top half for veg and the bottom for flower? that would leave only 3 feet of vertical growth for the flower part. pretty small plants since i have a 400watter that i plan to bake around cool w/ 265 dayton. (i also have a t5 and a 125 dayton for the veg part). would only two feet of vertical be enough to veg and four feet vertical be enough to flower? 6ftx4ftx1.6ft sounds like it should be big enough to handle the job. what do you guys on this board think? how would you build it?

which cabinet from lowes are you refering to?

the 72"h 20"d 48"w stor it all.

That should be sufficient enough room for both veg and flowering. Remember it's all about how you crop your plants so that you get maximum flowering potential. Or so i've read.