FYI, White color light is for vegging not flowering, and Warmer light is for flowering not vegging! Apart from that go read journals, look for shackleford.r, he just built a cabinet to go in a closet, he can help you with questions but do search for yourself and find the majority out, then ask for clarification. Dont just say I want to grow write me a list of materials, websites i can buy from, loan me the cash and come build my room.
Also if this is your first grow remember not everyone on here knows their shit, double check everything! Or at least check their post count, or if they have any successful grows.
Apart from that, gt out of the metal box if you can, the heat will radiate from the metal walls and you will need a lot of airflow. If you have a refrigerated air con, or you live somewhere cold you could cool the whole thing from the outside if you could keep cold enough air moving over the cabinet. Like a giant heatsink.
In all honesty people have grown in cardboard boxes. If you cant cool the metal box get some big packing boxes, coat the inside with mylar and stack them 2 high over the top of your plants for height. Easy to cut, easy to repair, easy to move, easy to cool. Just don't get them wet. If they get o hot in the cardboard boxes take the boxes off for 10 mins, all the heats now gone and you can start again, with better cooling.
For cardboard boxes I wold go on ebay and buy:
some big pc case fans (case fans not cpu)
a 110/220v - 12v adapter...usb charger is correct voltage and amperage, and cheap too!
Spend the rest of your cash on lights. Get ph test strips, no point having a $150 ph meter when your growing in a cardboard box. You wont need ec/ppm meter because if you go hydro you wont have money for anything. (you need air and water pumps, hose and connectors etc...its not cheap) I know as i just went from soil myself, to hydro.
I started like you, except i built a box from timber and I went over budget to get a 400w hps...It cost like $60 more than I would have spent on CFL but it made more than $60 worth of weed difference. Once again you arent going to cool that metal box with a HID light in it tho.
Long story short:
You will do fine! But you cant just say "I want a phat 'dro setup, gon' cook me up some kind bud" (or whatever the kids call it where you are at). Start of with "I want to get set up as cheap as I can, grow something i might be able to keep alive till the end, then with the money i save on the ounce i grew we can start some upgrades."
Then your second grow you will have whatever money you save from not buying weed from the first, use that to buy something you need. rinse and repeat till you have an awesome room.
A guy on here K1ng, started in his closet with a cardboard box and some cfls, hes now 100% hydroponic, and putting out pounds. We all start out saying we just want a cheap easy way to grow bud but its too easy to upgrade these rooms man. I have subscribed, I will help you whatever you choose...but know I'm not saying this to make you feel overwhelmed, but Ive read soooo many journals of people trying to do too much their first time, and its frustrating when you spent your oz cash on a setup, and 6 weeks in they are 30 cm tall with 2 sets of leaves yellow as bananas, pouring straight nutrients in to try to get the poor plants to uptake...really just worsening the problem...
Go into this venture knowing that if you do manage to keep the babies alive through your first grow you wont have pounds of weed. You may get oz(s). I got 4 oz with no real veg time off 4 plants, with a 400w hps in a few months. That was in soil/perlite.
Check my grow, If you can find your way to it have a look at my old one! I made mistakes that you may be able to learn from! It was called 400w hps grow box. i think.
prot
P.S. The second grow is EXPONENTIALLY BETTER. My plants are already after 2 weeks (from seed) bigger than my last plants were 7 weeks into veg. I was WAY overwatering. Its so hard to leave them alone man! You think the more water the faster they grow...so wrong lol. I should have put an electric fence around my grow box to save them from me lol...but they survived, eventually i stfu and let people tell me what I was doing wrong and all of a sudden they took off...I remember thinking "this is taking ages"...next thing i knew they had buds, then all of a sudden I was out buying a microscope to check trichs, then they were ready and I was cutting them down!
