How do we move forward with a Nephele evaluation and purchase?

All you need to do is to sign up for an evaluation. The sign-up page explains the process. Essentially, you have a thirty day trial period that begins upon signup, after which you begin the subscription for the package that you selected. Immediately upon signup, you will receive instructions for accessing and logging in to your Orion server, together with login information for a support portal that provides you with download links to the Orion client libraries. The support portal includes a constantly-updated knowledgebase with helpful information for development and operations, as well as a ticketing system for submitting and managing problem reports, service requests and technical inquiries.