I got these LED bulbs from amazon. https://www.amazon.com/gp/aw/d/B01DJWRE ... UTF8&psc=1
A fellow Leaf owner wrote a nice review and instruction on how to install the bulbs. I installed these bulbs in my 2016 SV and it works pretty well. The low beam is ok but the high beam is amazingly bright. And you will have to adjust the light pattern.
Once you removed the dusk cover and the light bulb, you will see that there is a gap between the reflector housing and the exterior cover, I just push the connectors into the gap and I was able to put the dust cover back on. It was not easy, but it can be done.
I live in fairly cold climate, year round weather is 40 to 70F, so far I have not have problem with heating issue by putting the dust cover back on. Also, since there is no engine, so not much heat coming from the engine/motor bay. Keep the original bulb around just in case if you burn the LED bulbs. The blue color is pretty cool.