I would recommend A. Chadwick Thornhill’s The Chosen People: Election, Paul and Second Temple Judaism. I was provided a copy through a special release (directly from the publisher for the purpose of an online review).
My favorite quote is when Thornhill suggests, “Paul has not argued that God has predetermined certain individuals to eternal life and others to eternal death. Rather God foresaw that he would form a people and determined the goal of their development, which is conformity to Christ. Furthermore, God has not defined inclusion among the elect people of God in terms of ancestry or keeping the law, but has defined the “boundary marker” of God’s people as faith in Jesus the Messiah” (253).
For more information, check out the author’s blog (and let me know what you think of the book).