Hi Ravijeet
AFAIK, there is no standard PI/PO content for Concur at the moment, neither have I seen any in the Roadmap so far.
My blog that you referenced only covers integration for SAE. There are a lot of other APIs available in Concur for integration and it all depends on your specific business requirements. Unfortunately, all will have to be custom developed.
As for the Advantco REST adapter mentioned in the blog, that portion is interchangeable since the latest SPs now have similar functionality for SAP's own REST adapter, i.e. OAuth 2, sender side polling.
Rgds
Eng Swee