Old question and sorry I didn't see it. I have 47 plumeria, most grown from cuttings, and have several T5HO 2x4 lights with blue and red lamps. They do marvelously.

If you are just getting started and have just a few cuttings, something like this would get you going. But be sure that for a four light fixture you use two red spectrum lamps for flowering. Plumeria are highly addictive and grow quickly.

https://www.amazon.com/Agrobrite-Designer-FLP24-4-Tube-Fixture/dp/B007FGE6C0/ref=sr_1_fkmr0_1?ie=UTF8&qid=1512287125&sr=8-1-fkmr0&keywords=t5ho%2Bfixture%2Bagrobrite&th=1

These would be the red spectrum lights.

https://www.amazon.com/gp/product/B01731MNBW/ref=ox_sc_sfl_title_8?ie=UTF8&psc=1&smid=A2PQGFJXAT8J9K

If you have just one plant this LED light is wonderful. I grow citrus under them.

https://www.amazon.com/TaoTronics-Lights-Hydroponics-Organic-Applicable/dp/B01HPIPM70/ref=sr_1_4?s=lawn-garden&ie=UTF8&qid=1512287677&sr=1-4&keywords=taotronics+36w+led+grow+light+bulb

with this:

https://www.amazon.com/Lantern-Pendant-Light-Extension-Switch/dp/B014TN6JLC/ref=sr_1_6?ie=UTF8&qid=1512287799&sr=8-6&keywords=pendant+light+plug

I picked up a 300w LED for two plants and it seems to be working for one of them as it’s continuing to grow leaves. However, I’m not sure if the other plant is going dormant or exhibiting symptoms of burning from the light. This plant is slightly taller than the other one so it’s closer to the light (around 15 inches of distance from the light). Any thoughts?

I grow plumeria but never under lights, it doesn't look good. I would let those leaves drop off and have it push out another set.