I used the LED shoplight sold at Costco and it seemed to work just fine.

I'm assuming this is a commercial venture?

Two dozen trays, indoors, would require a lot of lights - regardless of what type of light you choose. A lot of electricity, too, for that length of time. I use (4) 6-bulb T8 high-bay fixtures (from Home Depot), which use 200 watts each & together support 12 trays... and you need twice that.

Shop lights or regular T8 bulbs would work (I used T12 shop lights for years) but they need to be suspended very closely above the plants, and are not very energy efficient. Even at one 2-bulb fixture per two trays (which would be poor light coverage) you would be looking at 700-800 watts. Realistically, to get good growth, you would probably need twice that... which could push the limits of a standard electrical circuit. It would also generate a lot of waste heat, which would require continuous ventilation.

LEDs would greatly reduce both energy consumption & heat generation, but would cost significantly more than fluorescent. LED bulbs which fit into T8 fixtures are becoming more widely available & competition is driving the price down; but they are still not cheap. Not sure what your intended budget is, but that could be quite a large initial outlay.

You might want to consider a hybrid setup. Fewer lights for seed starting, and a small heated solar greenhouse (or hot bed) once the seedlings get larger. I use such a setup for raising large numbers of vegetable transplants, starting them in waves beginning with slow growing, cool tolerant plants, and as those are moved outside, replacing them under the lights with faster-growing heat lovers. Timed right, they all end up in the greenhouse just before transplanting. Harbor Freight carries some affordable greenhouse kits; the one I use ends up with about 24 trays (albeit a tight fit), the larger one would easily hold 24 trays with more room to move.

Thank you! I’ll look into your suggestions!

I see Home Depot has the lights you suggested, only 20 watt, I don’t see 200 Watt.

The fixture is from Home Depot, and holds six T8 bulbs (the bulbs & appliance cord are not included).

Metalux high bay fixture

The bulbs I use were purchased separately, and use 32 watts each, for a total of about 200 watts per fixture. I purchased the bulbs online; all of the bulbs offered locally had low light output (I had used 3000+ lumens per bulb for the T12's). HO T8's are also pricey, but I found some economical 3000+ lumen bulbs here:

Goodlite T8

My only complaint about the bulbs is a yin/yang. They were bright enough to cause leaf burn if placed too closely; but as a result, the transplants were very easy to harden off once placed outside. The intensity was bright enough that the onion seedlings did not get leggy.