^^^ What he said. First figure out how much you want/need to produce and where it will be regarding space and ventilation. The Home Depot cabinets are a great place to start.. You can get one that has a decent footprint and yield capability, but as said above can be tough to cool when using a larger (250+W) light. Hydro is a much higher maintenance system and more costly to set up, and the only advantages I saw over soil were quicker vegging - the flower time is the same (strain dependant) for either system. I've seen soil outdo hydro watt for watt, and vice-versa, all depending on the grower and ambient conditions. 7-8 foot tall is uneccessary, as you can use LST or SCROG/SOG type techniques to keep the height down and maximize yield. Make sure you get a good fan ( ie. quiet and powerful) and a carbon/charcoal filter one size larger than they recommend =D. Good luck and search, search search - tons of good information here!