I suggest the following and I do this with trepidation.. I am guessing your budget is small and your space is small and you just want to grow some tomatoes for your own salad, your not opening a victory garden or a vegetable stand... Compact Flourescents or regular ole cool white flourescents (40Watt 4 feet,etc..).. Don't use sack weed, Now I am sure you could get some sack weed that is good, but why waste your first grow on that risk.. Get some inexpensive Nirvana seeds... get a strain that is a so called idiot proof strain.. I would reccomend any Northern Light strain (NL5, Big Buds, etc..).. If you have the money for a good light... go to HTGSupply.com and get yourself a budget light you can get a 400WATT HPS for $119.00. Consider this a INVESTMENT, you will grow better and more tomatoes with the right light.. thus you will get your money back.. considering how much an ounce of tomatoes cost.. Google is your friend, also check OVERGROW.COM