You don't need a cold source or anything man I have mine venting in from my room mates room i mean granted its right by the window which we leave open now that its summer, but yeah the ducting just hangs out the bottom of the closet for veg and I've put a passive intake and exhaust in so all in all that works fine for my cfl veg tent but if it doesn't I just freeze some 6L milk bottles and put them in my tent right by the pots, so long as they are sealed and it doesn't create a shit ton too much humidity its fine like you could probably just use a bunch of frozen peas if you didn't have any bottles lying around, just beware if you hang things they will drip. Really like you can figure out almost anything with a little common sense you don't have to spend a bunch of money on expensive kits and stuff just take an hour or two to research different methods of doing things before you invest your time and effort in it because its pretty shitty when things don't work. But immediately you just need your
seeds/clones
growth media
tent/room
pots (or solo cups for the first while)
nutrients (although you probably won't need these for the first week or so at least if your growing from seed)
some vague form of ventilation (could just be an open window although beware of bugs)
an oscillating fan (but thats also not really important for the first week)
lights for the start so cfl probably
and ph and ppm testing kits (I use like a drip ph test kit rather than digital because its cheap as hell and finding a cheap ppm meter on amazon is a piece of cake all in all should be $10 for both)
timers (like for your sockets to turn the lights on and off)
the rest can really pretty much be done as it goes on like when you need it, it is nice to plan ahead a bit because it saves you freaking out later looking for shit and possibly buying things at a higher than necessary price but on the plus side if you only buy things when you need them you won't buy any useless shite like I ended up with (little tip here just cos don't ask your room mates or anyone to give you a hand going out to the shops to buy things if you're the one planning everything because you will end invariably up spending more than you need)
The main thing you need to figure out is how many plants you plan on growing because all your equipment should be directly for that, for instance I have 2 plants in my veg room and 3 in flowering and I use a 200W CFL on 18/6 and a 250W HPS for flowering which has been easily enough for me so I'm not going to even think about going up to 600W because not only would it be more than twice as expensive to run it would also give me heat problems not to mention having to buy a better ballast and everything. Bigger isn't always better thats all I'm saying you just need to find the right size and i mean I have two tents up and working for ~$780 so one tent for 1000 although its undoubtedly probably got more powerful lights and vents than I do I have 2 tents so I can grow a mother out properly and take clones and run a perpetual grow plus I know how everything works because I set it all up so if theres a problem I know I can fix fix it... especially with all these useless spare parts lying around just waiting for me to take them apart. haha