"I have heard indicas are better for nighttime smoking, what would be a good strain?"
I discourage smoking, because when you burn weed, you are making carbon monoxide, tar, and carcinogens. If you use a lighter, you are inhaling butane. All of these chemicals are toxic and may be harmful.
So, if you want a fast-acting medication, I suggest vaporizing. Keep in mind that the sedative effects of vaporized cannabis will only last for an hour or two. If you find that you are waking up in the middle of the night with difficulty staying asleep, I would recommend an edible formulation, which will last up to 6-8 hours and hopefully allow a full night’s sleep.
Indica strains are, in general, much more relaxing and sleep-inducing than sativa strains. There are many. Some suggestions include "purple," "OG," and "kush" strains. You can always ask other members of your collective / bud tenders to help point you in the right direction.