Yes, Ariba 9R1/9R2 refer to on-premise and 13s/14s refer to on-demand releases. For your question about mapping business requirements to Ariba requirements, it's best to contact the Ariba Administrator at ConAgra.
It sounds like you're interested in learning more about Ariba's suite of solutions. You can get an introduction to Ariba via OpenSAP training recordings. Here's a link to the Introduction to Ariba course: https://open.sap.com/courses/bnar1
There are a variety of programs for Ariba and Procurement available at the SAP Learning Hub. The Hub offers self-paced eLearning versions for most of the Ariba classes. You can identify them by the "e" in the name, for example AR510e is the e-Learning version of AR510. Here's a link to the e-Learning catalog: https://training.sap.com/shop/sap-search?q=*&refine%5Bsolution%5D%5BCloud%5D=Cloud&refine%5Bsub-solution%5D%5BAriba%5D=Ariba
Ariba Procure-to-Pay certification launched in April 2016. You can learn more about the program at this blog: http://scn.sap.com/community/training-and-education/certification/blog/2016/04/20/sap-ariba-has-arrived-with-certification-in-the-cloud-for-ariba-procure-to-pay
SAP Ariba Exchange Community Manager