Need some ideas/input on a growbox help much appreciated

i have indica dominant seeds. which is good for me because i want to grow short bushy plants. i have a 2ft 8bulb t5 fixture for flowering and i want to get the 2 ft t5 tek lamp from htgsupply for vegging. for ventilation i was going to get the 4" fan and carbon filter combo with a speed controller and use it to ventilate both boxes. i know i need atleast a 24"x28" floor space for my flowering lamp to fit im not sure on the height though. i was thinking 3ft tall?
and how much space do i need for vegging 2 plants and keeping a mother healthy? 2x2x3ft?

thanks for any help

does anyone have any input on how tall my grow box should be? anyone at all