Get some Samsung F-series or H-InFlux strips and you got top level lighting. With strips you hget a much better spread of the light. Which means you can go much closer than with COBs or QB's. Which in turn means less wall losses and much better penetration of the light through the canopy.
I would at least attach some aluminum angles or preferably U-channels though. That gives you an easy to assemble frame and some more rigidity.
If you go for CXB3590 @ 50W then you would need about 60 of them to cover that space. I personally found it a lot easier to do this with strips.
They have 112cm strips and 56cm strips. Two 112cm strips plus a 56cm would nicely cover 3m. With these strips you need about 320W per m2 if you run them slightly below tested amps (for the F-series) or the H-influx at tested amps.
For instance with F-series, 22 112cm strips plus 11 56cm strips would fill that space.
Check ledgardener.com for some examples on how to design a frame, or check out the many build reports and diy threads showing strip lights.
those strip lights are for micro grows. They have terrible intensity they need to be less than 8 inches away from the canopy which kills coverage.
That's is still complete bullshit. You clearly know nothing, Yoda Snow.