I have been informed that the early-mid 20th century theologian Karl Barth is a good place to dip, (not easy reading though, there aren't any pictures). I have done so here.
This seems to be the pivotal phrase in his writing on election and double predestination: Jesus Christ is the electing God and He is also the elected Man.
It will be a while before I have some concrete thoughts on this, but if anyone wants to ponder this with me a while, then please do. And do ask me about it, as it will help me to sort out my thoughts on what I am reading.