There is way too much info on here about lighting to be able to ask such a vague question. How about you say what your budget looks like (including power bill) and then we can help. If you are going to buy CFL's, buy a lot of them. I use the cheap aluminum clip lights you can buy at every home depot or lowes. Get them close. You don't want to be able to see the plant much, you want to see only metal reflector and light bulb. Get the lights close in other words. Real close. I put a fan right on my plants because some of the leaves grow right into the bulb, within a day. Definitely switch to 2700k bulbs when you go 12/12. Most of the energy saving lights are 2700k because it takes less energy to put out as much light at the lower color temp. You can buy 150w replacements for 9 bucks. Or buy the standard 100w replacements and buy a lot. I got through the veg stage very successfully with 2 300w replacement bulbs. For flowering I left those lights but added 3 more 15 w replacements. This is for 2 plants one of which is an LST plant. I find this to be the best way to maximize light on the right parts of the plant. I also groomed another plant to be very bushy as in it has about 5 colas, 4 real strong ones. My power bill went up 20 bucks with 3 lights on 24 hours. Now in 12/12 I am adding lights so it will remain pretty much the same.
If you want to grow 8'x2' with HID's then your bill will be more than mine. Probably a lot more since you will probably be told to get 400w of HID which you will have on from 18 to 24 hrs a day. This can add up. Do this during the summer and forget your air conditioner to avoid any electric company scrutiny.
I am now grooming a plant to grow in a pot LST style but I will put it outside all day and inside at night. Free light. 24 hrs for 4 weeks and then flower by leaving it outside for 12 hours then into a closet in the dark.
Be creative. Bring more experimental knowledge to the forum. Don't be a cookie cutter operation. This is an art and a lifestyle. So go out and buy some lights.
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