I am running one Spider Farmer SF2000, and the rest of my lights are Mars Hydro (TS600, TSW2000, and TS3000). I would avoid the cheaper off name brands though and stick with lights people actually use and can give a good review of. From what I've noticed, anything below about 18" from the top of your plant will usually be smaller no matter what light you use. As long as you get good quality lights you shouldn't have a problem with good penetration. I just bought my lights recently, replaced some 315CMH lights, which replaced an HPS and cheap LED light combo. So far I love them! For your 3x3, look at the Mars Hydro TSW2000. I have 4 of them in my 8x8 tent and so far they're doing great. Another thing I'll add is to spend the money up front, it will be worth it and will actually save you money spent on buying multiple cheap lights because the last ones didn't work. Trust me, I did that exact thing that's why I had so many different kinds. It cost me way more in the long run than if I would have just spent the money in the beginning.