well that cabinet would work good for clones and such unless you want to take out the shelves because you definately dont have the height to grow in there if youleave them in. so that brings me to the poitn of if you are nto going to use the shelves why bother buys it. you can build something much cheaper. I prefer wood anyways, if you use a metal cabinet that could contribute to heating issues. You can choose to do wot you like but I can tell you wot my first cab I designed was.
I basically built a frame out of 2x3's I didnt see using 2x4 necessary and they where much more expensive.
I was building this to accomadate 12 plants but you can do it on a smaller scale or built it the same size and split it and make a flower and veggie area.
my dimesions where : 6'l x6'hx3.5'd these are the measurements from the inside of the cabinet. I used some cheap 1/2 plywood on the top bottom and two sides the fron t I left open using a heavey duty drop cloth ( which I actually switche dto panda film and I recommend) but either way you can get away with the drop cloth is you over lap it. I mainly did this due to venting issues I was having, but if you are looking for a more secure set up then make the from a double cabinet door to open up that way you can lock it too if you need. i am not familar wtih bubbleponics as I use soil ( soon to be ebb n flow) but I make sure I have atleast 3.5 feet of actual grow space after the pot is already in there, I also have cooltubes on my setup so this is very helpful and allows me to get away with a little bit shorter vertical space. now because I prefer to keep my light stationary I have put in some extra beam ( see pic below) so I can actually move the level of the floor depending on how far I need my plants from the light.. I used soem nice reflective insulation on my walls and ceiling and have 2.5' passive airholes drilled the whole way around. I then added a 6'' exhuast fan in the midright side ( again see pic) and I have a 6" inline fan hooke to my cooltubes and vented to the outside of the cab. oscillating fan in 2 corners and humidifier in there as well Ihave issues keeping my humidity above 20% this is why I added that, this may not be your case you will have to test ur cab out and make adjust ments along the way. One thing I can tell you is definately get ur set up done before you even germinate it will save you a headache. hope u can ge tsum good ideas fromthis. GL if you have any ??? just shoot.