Crampygut - let us know how the magnesium, ZMA works out. I take magnesium, have for awhile, but don't know if it or other items taken helped most with improved rest. When I began taking magnesium I also changed my diet similar to the SCD, plus began using other supplements useful for sleep. Melatonin is for sale in America & I take 3mg of time release in the evening.
I have a few relatives that rely largely on taking magnesium in the evening for a good nights rest. It works very well for them.
It is kind of cute also in that recently I purchased one of those alarm clocks that simulates sunlight. I believe it is called a SAD light. It's great, it does a good job of waking me up. Maybe not the correct way to describe it, but the bright light removes melatonin from the system. The cute part is the cats come into the room in the morning anymore. When the light turns on, and gradually increases in intensity, they begin purring away. The two of them have become the sound part of the wake up light clock.
Not to post to many articles, but saw on Emily Dean's sight a nice write up about the importance of light and dark on a good nights sleep, not only for animals and humans too.
"Sunshine and Sad Hamsters"
http://evolutionarypsychiatry.blogspot.com/2013/08/sunshine-and-sad-hamsters.html
I guess before I forget, I have found also that when I eat chicken and eggs I sleep poorly. Both are trigger foods for me too so not surprising that I would have a restless night from that.