Paul and Apostolic Identity – need some help/advice

My penultimate chapter that I am working on deals with Paul’s self-conception of his apostleship and where he derived this understanding from and how it developed in the articulation of his status and ‘calling’ in his letters.

The only thing I know of that is substantial is Shutz’s Paul and the Anatomy of Apostolic Authority.  Does anyone know of other good resources?  I am more interested in the generation and development of his apostolic identity, rather than more current interests in social dynamics (i.e. Paul and ‘power’).  More specificially, I am studying the importance of the metaphors of Paul as ‘temple architect’ (see 1 Cor 3; Rom 15) and Paul as ‘priest’ (1 Cor 9; Rom 15) – are these just convenient metaphors or are they more formative in his identity?  Where did he get these ideas from?  Please help!
Any suggestion would be most welcome, but presume I have read basic dictionary entries and commentaries.  Thanks!