I honestly think that (if it fits into your schedule) you might benefit from working out in the morning.  Once you get into the habit of it you'll have more energy during the day and I've found that when I'm exercising regularly I fall asleep more easily and sleep through the night more.  If I work out at night I tend to be too keyed up for sleep...& try something cardiovascular where you get your breathing up to a rhythmic but comfortable rate.   I've always been a poor sleeper, insomnia, can't get up in the morning...and when I'm active in the mornings the whole flow of the rest of the day goes smoother.