Perhaps only use it for a couple of chips and a driver. I would suggest you keep looking and visit junk yards. Old audio Amps have great heat sinks on the back and the cases can be used to house things, generally you would take the heat sinks off the back and put them in the top or bottom and use the power cord etc. Have a look around for a dead amp to strip, most of the better ones (in their day) have almost everything you need. Use the flat sides of the heat sink(s) to mount the LEDs and if you have 2 heat sinks or can saw one in half, you can spread them out to the sides, each sink with 3 chips. There might even be enough room in the middle of the box to put a couple of more chips on PC CPU heat sinks and expand to an 8 LED unit with 4 drivers in the box. That would give you close to 400 real watts of power for a central top light,it might be all the top light you need for a 4X4. Your own DIY high end, high power grow light that if you bought it new online, they would claim was a 600 or 800 watt unit and cost many hundreds of dollars. If you got the right amp for free or a few bucks, four drivers and 8 warm white chips (add one cool white to the mix instead of a warm white) it would cost a little over a hundred bucks US.