Honestly, between economies of scale and supply side issues, you're just as well off buying a pre-built luminair. DIY isn't what it used to be.
HLG, Vipar Spectra, Medicgrow, hell even MarsHydro has way upped their game. Shoot for 40 watts per square foot in flower. The vast majority of...
Try raising your temperature to 84 degrees. Just to see if that fixes things.
Alternatively, a couple guys on here consistently run their grows well outside optimal vpd and they get great results. Maybe dial in physical environment until your plants are happy and let them run. Doesn't really...
Don't think box fans will have the static pressure to do much good in this application. Name brand seems overly expensive for sure, but some of that is the fans.
2nd on the Motorbreath. Haven't grown it, but the Mb I've had reeks of used motor oil and bad breath. Absolutely zero fruit of any kind. GMO is also not fruity ime.
Also, and not for nothing, those herbs look MIGHTY rough.
I mean, if it's my product, I put the fresh herbs in there, make my growin' fridge look something special.
You could also do a series - parallel circuit with lower voltage parts. 3 24 volt parts in series, then to the driver. Check my math. Think the new Samsung 90 cri are 24 volt parts.