The hlg kits are excellent introduction to diy lighting. They send everything you need, and you can even find some assembly videos on youtube. Pretty much risk and hassle free.
The only real downfall to the kits is that you pay about a $40-$60 premium for the buy it all in one shot at one place. For a lot of people though they find a lot more confidence in doing that. These kits are really more of assemble yourself than do it yourself, and there’s a lot to be said for that. Especially for your first project.
Hlg now offers a new heatsink that flips the orientation of the boards 90 degrees, you’ll want to make sure you get the older design if going that route. Probably what they refer to as 260 watt xl kits, 2 of those would have good board spacing in a 4x4 to light it up very well.
Also, I think we’re about to see some new boards from hlg. So if you’re not in a big hurry, maybe standby for a bit. I’m thinking there will be 90 cri options, possibly a more efficient Samsung chip, and maybe even a different string ratio to change up voltage and currents.