Perpetual Harvest set up

Hey all, just wondering about what you think of my perpetual harvest plans, i.e. do you think it'll work the way I plan, suggestions for improving it, etc.

Basically I have a spare room in my house with a large closet in it, so my plan is to build a Mother Box in the closet with two 250w HPS lights in there side by side, and i'll cut two holes in the wall above the door on each side to put a 6" inline fan in each hole for the exhaust. I'll cut two 8'' holes in the wall on either side of the bottom of the door for in-take holes. I'll put a row of 4 mother plants in there, each plant a different strain so I have variety.
Then for the actual room, i'm going to build a veg box and a flower box. For each box I plan to keep the lights fixed at the top of the box and have 3 stair levels with 2 plants on each level. For a total of 6 plants growing in each box. I'm going to use a 600w Metal Halide for the Veg box and a 600w HPS for the flower box.

My main concerns are: would I be able to keep a mother plant in veg for like 45 days, then take clones, give it probably 15 days to recover/regrow and then flower it? That way after a couple of clone cycles I could separate the mother room into 2 rooms and flower 2 of the mothers, leaving the other two in veg for 90 more days to take clones until I have another two mothers at least 45 days old. (I don't want to just stick the mothers in the veg room after they recover because I don't want to disrupt the clone cycle.)
Would the two mothers be too big to keep under the 250w lights for that amount of time? cos if it's 45 days veg before I take clones off of them, and then 15 days for the other two to recover before I flower them, then 45 days of the other ones flowering. Cos that would be almost 4 months of veg for two plants, they would probably need a 250w each and a way bigger bucket than 5 gals too, wouldn't they?
Edit: another question: would it be better to use a 400w MH for veg and then a 600w HPS for flowering? Since the plants won't be as big in the veg box as they'll get in the flower box, right? Or is it better to use the same wattage for both boxes? I read a couple people using 400w for veg and then 600w for flowering, just wondering if I should do the same to help cut down energy costs.
Either way I want to have 6 plants going in veg and flower at the same time.

I use a 400w mh for veg and then a 600w and a 400w hps for flowering. I like to continually increase the amount of light over the course of a plants life, or specifically from veg to flower. This round I did eessentially what you are talking about. I had two mothers(that were clones) vegged them over a month while my whole flowering tent finished up and was cleaned. Then took18 clones and let them recover a week, then transplanted from 4 gallon pots to 10 gallon pots for flower. Vegged another week in the bigger pots and then flipped them. I always like to leave plants alone for at least a week before I do anything more to shock them. For example I dont transplant and switch lights at the same time. Sounds like most of what you want to do is pretty doable.

Sweet! Thanks for the feedback bro. I'm hoping to have all the materials for my grow at the start of January. I think I might add 2 4ft T5 fixtures with 2 tubes in each one diagonally along the stair pattern to add side lighting for the flowering room. I'm really stoked to set my room up. I just wanna wait until I have enough money to build the whole thing all at once and have a few hundred extra in case of extra costs.

So how did this turn out?