do a google search or forum search.. your question is asking too much and no one want to teach you what you can just read on your own... get a basic concept first by reading then post your questions... you just asked a very broad question! first ask yourself how much can you offord... then do your research... not only do some lights need to be cooled we dont know anything about your growing space.. we dont know what kind your growing... you say 4 plants? 4 1 foot plants or 4 6 foot plants? see what i mean? do about 3 or 4 months of reading people forums and threads posting questions about their set ups... then take from it what you want and give it a shot... and beware of misinformed people telling you bogus methods... a good way of getting a feel for this is being able to tell whats right and wrong.. like my title.. what wrong with that? when you can answer that question youll know why your question is too broad...
