I know the problem : you either get books on the science vs faith theme or you find books trying to vindicate the rationality of (usually Christian) faith. Something less polemical or 'apologetic' and more conceptual is required. Try any or all of these :
Basil Mitchell : How to Play Theological Ping-Pong: And Other Essays on Faith and Reason
Published by Eerdmans Pub Co
ISBN 10: 0802805442 ISBN 13: 9780802805447
Paul Helm :Faith and Understanding (Reason & Religion) (Reason and Religion)
ISBN 10: 0748609229 / ISBN 13: 9780748609222
Published by Edinburgh University Press 01/07/1997, 1997
J. Webber : Philosophy of Religion 3: Faith and Reason
ISBN 10: 1898653097 / ISBN 13: 9781898653097
Published by Abacus Educational Services, 1995
Roger Trigg : RATIONALITY & RELIGION: Does Faith Need Reason?
ISBN 10: 0631197486 / ISBN 13: 9780631197485
Published by John Wiley & Sons, 1998
Ninian Smart :Reasons and Faiths (International Library of Psychology)
ISBN 10: 0710031556 / ISBN 13: 9780710031556
Published by Routledge & Kegan Paul PLC, London, 1958
C. Michalson : The Rationality of Faith: An Historical Critique of Theological Reason
Published by SCM (1964)
John A Hutchison : Faith, Reason and Existence
Published by Oxford University Press, New York USA (1956)
I don't think there is an ideal book but you should find something of what you want in at least one or some of these.