Its not too difficult to build your own if you are into DIY.
I have build about three grow lights using Samsung FSERIES GEN3 4000K light strips and when ran at 90% of max they are rated for 165 lumens/Watt which converts to ~2.7 µmol/joule - basically about as efficient as you can get.
My most recent build was:
- 6 x Samsung FSERIES GEN3 4000K (SI-B8T261560WW) strips (~$10 per 2’ strip, $60 total)
- Meanwell HLG-240H-24A LED power supply (~$50 on eBay)
- Aluminum C-CHANNEL 3/4x9/16x1/16 - 96" ($11 from Home Depot)
- 20mm Double Side Adhesive Thermal Conductive Tape ($14 on Amazon)
- Aluminum Angle 3/4x1/20 - 96" ($11 from Home Depot)
- Various wiring and hanging hardware
You just need to figure out how you want to organize and space out the strips in advance and build the frame - which is what I use the aluminum angle for. LED strips are adhered to the Aluminum C-channel with the double side thermal tape and the Aluminum C-channel doubles as a heat sink. Then its a matter of wiring up the LED strips to the LED power supply.
Ran at 90% of max my lights specs are: 23.7 Volt, 9.45 Amp = 224.1 Watts and that covers a 2 x 6’ area to provides excellent growth for seedings.
EDIT: Here are the two blog posts that got me started: