I went with the growlab after lots of research... growlab is made by homebox (my 2nd choice) but it is an upgrade...i was considering making one too but then i thought... whats $400 compared to all the zones this thing is going to make... (I got the 4x8 tent BTW).
has 8" duct openings with draw strings all over it... can run 4" duct and just pull the draw string to make it light and air tight... beautiful.
they are completely light tight, and the inside is completely reflective, including the floor, which is also designed to contain a pretty large water spill.. (should hold 4" of water on the 4x8 surface - i just googled it, that is 80 gallons)
i'm running 2KW in my tent, and a can filter with 33 lbs of carbon in it... whole filter is like 50 lbs... plus an inline fan, which i will hang from the ceiling of the tent, with the oversize light hoods... something you'll have to consider when building your own... i wouldn't hang all that shit on pvc, so you might have to re-arrange or re-inforce something.
the grow lab also has windows on the front of the tent, that velcro shut... i didnt think i would like them, but they are actually quite helpful for taking a quick peek in the tent without opening it up... its actually quite hard to tell if the lights are on inside or not.
anyways, tents are the shit... i've actually got 2 growlabs... one is for the moms/clones...
sun hut is one i've only recently heard of - they are more expensive that the grow lab, but possibly slightly heavier...
either way... the home made grow tent will in no way compete with any of the big names... but it will still grow some shit like mad if you do it right... the scotch tape holding the face of it on will only last for so long... having a good tent is just for peace of mind... and the fact that you can re-use it after you disassemble.
peace